lv_examle: renames, add 'lv_ex_' prefix

lv_examples/1_2_objects/lv_ex_objects.c

@@ -57,7 +57,7 @@
 /*********************
  *      INCLUDES
  *********************/
-#include "obj_usage.h"
+#include "lv_ex_objects.h"
 #if USE_LV_EXAMPLE != 0
 
 #include "lvgl/lvgl.h"
@@ -91,7 +91,7 @@ static  lv_action_res_t ddlist_action(lv_obj_t * ddlist, lv_dispi_t * dispi);
 /**
  * Initialize the Object usage example
  */
-void lv_obj_usage_init(void)
+void lv_ex_objects(void)
 {
 
     /********************

lv_examples/1_3_styles/lv_ex_styles.h

@@ -27,7 +27,7 @@ extern "C" {
 /**********************
  * GLOBAL PROTOTYPES
  **********************/
-void style_usage_init(void);
+void lv_ex_styles(void);
 
 /**********************
  *      MACROS

lv_examples/2_2_encoder_ctrl/lv_ex_encoder_ctrl.c

@@ -1,5 +1,5 @@
 /**
- * @file encoder_ctrl.c
+ * @file lv_ex_encoder_ctrl.c
  *
  */
 
@@ -33,7 +33,7 @@
 /*********************
  *      INCLUDES
  *********************/
-#include "encoder_ctrl.h"
+#include "lv_ex_encoder_ctrl.h"
 #if USE_LV_EXAMPLE != 0
 
 #include "lvgl/lvgl.h"
@@ -78,7 +78,7 @@ static lv_group_t * g;              /*An Object Group*/
 /**
  * Create a simple GUI to demonstrate encoder control capability
  */
-void encoder_ctrl_init(void)
+void lv_ex_encoder_ctrl(void)
 {
     /* Create a Page screen (to make it scrollable)
      * and use Pretty layout to make the content responsive.