feat(anim): add the function of getting global animation refresher timer (#3331)

* feat(anim): add dynamic setting animation refresh period support

* add lv_anim_get_refr_period

* add lv_anim_get_timer

Co-authored-by: pengyiqiang <pengyiqiang@xiaomi.com>

src/misc/lv_anim.c

@@ -177,6 +177,11 @@ lv_anim_t * lv_anim_get(void * var, lv_anim_exec_xcb_t exec_cb)
     return NULL;
 }
 
+struct _lv_timer_t * lv_anim_get_timer(void)
+{
+    return _lv_anim_tmr;
+}
+
 uint16_t lv_anim_count_running(void)
 {
     uint16_t cnt = 0;

src/misc/lv_anim.h

@@ -40,6 +40,7 @@ typedef enum {
 } lv_anim_enable_t;
 
 struct _lv_anim_t;
+struct _lv_timer_t;
 
 /** Get the current value during an animation*/
 typedef int32_t (*lv_anim_path_cb_t)(const struct _lv_anim_t *);
@@ -345,6 +346,12 @@ void lv_anim_del_all(void);
  */
 lv_anim_t * lv_anim_get(void * var, lv_anim_exec_xcb_t exec_cb);
 
+/**
+ * Get global animation refresher timer.
+ * @return pointer to the animation refresher timer.
+ */
+struct _lv_timer_t * lv_anim_get_timer(void);
+
 /**
  * Delete an animation by getting the animated variable from `a`.
  * Only animations with `exec_cb` will be deleted.