ARM: at91: fix LCD-wiring mode

Fix regression introduced by commit 787f9fd2 ("atmel_lcdfb: support
16bit BGR:565 mode, remove unsupported 15bit modes") which broke 16-bpp
modes for older SOCs which use IBGR:555 (msb is intensity) rather than
BGR:565.

The above commit removes the RGB:555-wiring hack by
removing the no longer used ATMEL_LCDC_WIRING_RGB555 define.
Acked-by: NPeter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>

include/video/atmel_lcdc.h

@@ -30,7 +30,6 @@
  */
 #define ATMEL_LCDC_WIRING_BGR	0
 #define ATMEL_LCDC_WIRING_RGB	1
-#define ATMEL_LCDC_WIRING_RGB555	2
 
 
  /* LCD Controller info data structure, stored in device platform_data */