fix(micropython): missing bidi private header feature guard (#6801)

Co-authored-by: xlla <xllacyx@hotmail.com>

src/misc/lv_bidi_private.h

@@ -15,6 +15,7 @@ extern "C" {
  *********************/
 
 #include "lv_bidi.h"
+#if LV_USE_BIDI
 
 /*********************
  *      DEFINES
@@ -91,6 +92,8 @@ void lv_bidi_process_paragraph(const char * str_in, char * str_out, uint32_t len
  *      MACROS
  **********************/
 
+#endif /*LV_USE_BIDI*/
+
 #ifdef __cplusplus
 } /*extern "C"*/
 #endif