video: discard empty video_set_lut implementation

Discard the empty video_set_lut function from platform video
drivers.

This commit "69d275458893eaec35229b589092c2a6bde5440f" introduces
a weak function video_set_lut, so we do not need an strong function
in platform drivers, which does nothing.

Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

drivers/video/da8xx-fb.c

@@ -1035,16 +1035,6 @@ err_release_fb:
 	return NULL;
 }
 
-void video_set_lut(unsigned int index,	/* color number */
-		    unsigned char r,	/* red */
-		    unsigned char g,	/* green */
-		    unsigned char b	/* blue */
-		    )
-{
-
-	return;
-}
-
 void da8xx_video_init(const struct da8xx_panel *panel,
 		      const struct lcd_ctrl_config *lcd_cfg, int bits_pixel)
 {

drivers/video/mx3fb.c

@@ -904,12 +904,3 @@ void *video_hw_init(void)
 
 	return (void *) &panel;
 }
-
-void video_set_lut(unsigned int index,	/* color number */
-		    unsigned char r,	/* red */
-		    unsigned char g,	/* green */
-		    unsigned char b	/* blue */
-		    )
-{
-	return;
-}

drivers/video/mxc_ipuv3_fb.c

@@ -599,15 +599,6 @@ void *video_hw_init(void)
 	return (void *)&panel;
 }
 
-void video_set_lut(unsigned int index, /* color number */
-			unsigned char r,    /* red */
-			unsigned char g,    /* green */
-			unsigned char b     /* blue */
-			)
-{
-	return;
-}
-
 int ipuv3_fb_init(struct fb_videomode const *mode,
 		  uint8_t disp,
 		  uint32_t pixfmt)