Add lcd_set_bg_color_layer0

docs/lcd_api.md

@@ -104,7 +104,7 @@ void main(void) {
 #### Drawing text on the screen
 
 ```c
-void lcd_display_text(const char* text, uint16_t x_pos, uint16_t y_pos, uint32_t color, sFONT *font);
+void lcd_display_text(const char* text, uint16_t x_pos, uint16_t y_pos, uint32_t color, uint32_t bg_color, sFONT *font);
 ```
 
 ```c
@@ -116,7 +116,7 @@ void main(void) {
     ...
     lcd_init(true);
     ...
-    lcd_display_text("This is a text string.", 10, 10, LCD_GREEN, LCD_FONT16);
+    lcd_display_text("This is a text string.", 10, 10, LCD_GREEN, LCD_BLACK, LCD_FONT16);
 }
 ```
 Display text on the LCD screen in a certain color. When text width exceeds BSP_LCD_GetXSize(), a text wrap will be performed. If the text wrap is between two will be injected.
@@ -279,3 +279,20 @@ void main(void) {
 ```
 
 Clears all text strings on the LCD screen.
+
+#### Clearing (background/images) layer 0 to color
+```c
+void lcd_set_bg_color_layer0(uint32_t color);
+```
+
+```c
+#include "lcd_api.h"
+
+void main(void) {
+  ...
+  lcd_init(true);
+  lcd_draw_img_from_fs("st.bmp", 300, 100);
+  ...
+  lcd_set_bg_color_layer0(LCD_BLACK);
+}
+```