lcd: rename bitmap_plot to better represent its functionality

The name "bitmap_plot" is misleading because it implies that this is a generic
function capable of dealing with any bitmap, but its implementation only works
with the logo data.

Rename the function to better reflect this.

Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Bo Shen <voice.shen@atmel.com>
Tested-by: Josh Wu <josh.wu@atmel.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Anatolij Gustschin <agust@denx.de>

common/lcd.c

@@ -327,7 +327,7 @@ __weak void lcd_logo_set_cmap(void)
 		*cmap++ = bmp_logo_palette[i];
 }
 
-void bitmap_plot(int x, int y)
+void lcd_logo_plot(int x, int y)
 {
 	ushort i, j;
 	uchar *bmap = &bmp_logo_bitmap[0];
@@ -369,7 +369,7 @@ void bitmap_plot(int x, int y)
 	lcd_sync();
 }
 #else
-static inline void bitmap_plot(int x, int y) {}
+static inline void lcd_logo_plot(int x, int y) {}
 #endif /* CONFIG_LCD_LOGO */
 
 #if defined(CONFIG_CMD_BMP) || defined(CONFIG_SPLASH_SCREEN)
@@ -729,7 +729,7 @@ static void *lcd_logo(void)
 	}
 #endif /* CONFIG_SPLASH_SCREEN */
 
-	bitmap_plot(0, 0);
+	lcd_logo_plot(0, 0);
 
 #ifdef CONFIG_LCD_INFO
 	lcd_set_col(LCD_INFO_X / VIDEO_FONT_WIDTH);