lv_hal: use less general structur elements

lv_hal/lv_hal_indev.h

@@ -54,7 +54,7 @@ typedef struct {
 /*Initialized by the user and registered by 'lv_indev_add()'*/
 typedef struct {
     lv_hal_indev_type_t type;                       /*Input device type*/
-    bool (*get_data)(lv_indev_data_t *data);        /*Function pointer to read data. Return 'true' if there is still data to be read (buffered)*/
+    bool (*read_fp)(lv_indev_data_t *data);        /*Function pointer to read data. Return 'true' if there is still data to be read (buffered)*/
 }lv_indev_drv_t;
 
 struct _lv_obj_t;