fix warning in themes

src/lv_themes/lv_theme_empty.c

@@ -57,7 +57,7 @@ static lv_style_t opa_cover;
  * @return a pointer to reference this theme later
  */
 lv_theme_t * lv_theme_empty_init(lv_color_t color_primary, lv_color_t color_secondary, uint32_t flags,
-                                 lv_font_t * font_small, lv_font_t * font_normal, lv_font_t * font_subtitle, lv_font_t * font_title)
+        const lv_font_t * font_small, const lv_font_t * font_normal, const lv_font_t * font_subtitle, const lv_font_t * font_title)
 {
     lv_style_init(&opa_cover);
     lv_style_set_bg_opa(&opa_cover, LV_STATE_DEFAULT, LV_OPA_COVER);

src/lv_themes/lv_theme_empty.h

@@ -42,7 +42,7 @@ extern "C" {
  * @return a pointer to reference this theme later
  */
 lv_theme_t * lv_theme_empty_init(lv_color_t color_primary, lv_color_t color_secondary, uint32_t flags,
-                                 lv_font_t * font_small, lv_font_t * font_normal, lv_font_t * font_subtitle, lv_font_t * font_title);
+        const lv_font_t * font_small, const lv_font_t * font_normal, const lv_font_t * font_subtitle, const lv_font_t * font_title);
 /**********************
  *      MACROS
  **********************/

src/lv_themes/lv_theme_material.c

@@ -850,7 +850,7 @@ static void win_init(void)
  * @return a pointer to reference this theme later
  */
 lv_theme_t * lv_theme_material_init(lv_color_t color_primary, lv_color_t color_secondary, uint32_t flags,
-                                    lv_font_t * font_small, lv_font_t * font_normal, lv_font_t * font_subtitle, lv_font_t * font_title)
+                                    const lv_font_t * font_small, const lv_font_t * font_normal, const lv_font_t * font_subtitle, const lv_font_t * font_title)
 {
 
     theme.color_primary = color_primary;

src/lv_themes/lv_theme_material.h

@@ -46,7 +46,7 @@ typedef enum {
  * @return a pointer to reference this theme later
  */
 lv_theme_t * lv_theme_material_init(lv_color_t color_primary, lv_color_t color_secondary, uint32_t flags,
-                                    lv_font_t * font_small, lv_font_t * font_normal, lv_font_t * font_subtitle, lv_font_t * font_title);
+        const lv_font_t * font_small, const lv_font_t * font_normal, const lv_font_t * font_subtitle, const lv_font_t * font_title);
 /**********************
  *      MACROS
  **********************/

src/lv_themes/lv_theme_mono.c

@@ -485,7 +485,7 @@ static void win_init(void)
  * @return a pointer to reference this theme later
  */
 lv_theme_t * lv_theme_mono_init(lv_color_t color_primary, lv_color_t color_secondary, uint32_t flags,
-                                    lv_font_t * font_small, lv_font_t * font_normal, lv_font_t * font_subtitle, lv_font_t * font_title)
+        const lv_font_t * font_small, const lv_font_t * font_normal, const lv_font_t * font_subtitle, const lv_font_t * font_title)
 {
     theme.color_primary = color_primary;
     theme.color_secondary = color_secondary;

src/lv_themes/lv_theme_mono.h

@@ -42,7 +42,7 @@ extern "C" {
  * @return a pointer to reference this theme later
  */
 lv_theme_t * lv_theme_mono_init(lv_color_t color_primary, lv_color_t color_secondary, uint32_t flags,
-                                    lv_font_t * font_small, lv_font_t * font_normal, lv_font_t * font_subtitle, lv_font_t * font_title);
+        const lv_font_t * font_small, const lv_font_t * font_normal, const lv_font_t * font_subtitle, const lv_font_t * font_title);
 /**********************
  *      MACROS
  **********************/

src/lv_themes/lv_theme_template.c

@@ -340,7 +340,7 @@ static void win_init(void)
  * @return a pointer to reference this theme later
  */
 lv_theme_t * lv_theme_template_init(lv_color_t color_primary, lv_color_t color_secondary, uint32_t flags,
-                                    lv_font_t * font_small, lv_font_t * font_normal, lv_font_t * font_subtitle, lv_font_t * font_title)
+        const lv_font_t * font_small, const lv_font_t * font_normal, const lv_font_t * font_subtitle, const lv_font_t * font_title)
 {
 
     _color_primary = color_primary;

src/lv_themes/lv_theme_template.h

@@ -42,7 +42,7 @@ extern "C" {
  * @return a pointer to reference this theme later
  */
 lv_theme_t * lv_theme_template_init(lv_color_t color_primary, lv_color_t color_secondary, uint32_t flags,
-                                    lv_font_t * font_small, lv_font_t * font_normal, lv_font_t * font_subtitle, lv_font_t * font_title);
+        const lv_font_t * font_small, const lv_font_t * font_normal, const lv_font_t * font_subtitle, const lv_font_t * font_title);
 /**********************
  *      MACROS
  **********************/