colibri-imx6ull: fix vidargs

Unfortunately, that missing M makes the current downstream NXP BSP
4.14.98_2.0.0_ga crash early during Linux kernel boot. Fix this.
Signed-off-by: NMarcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: NOleksandr Suvorov <oleksandr.suvorov@toradex.com>
Reviewed-by: NIgor Opaniuk <igor.opaniuk@toradex.com>
Tested-by: NIgor Opaniuk <igor.opaniuk@toradex.com>

include/configs/colibri-imx6ull.h

@@ -123,7 +123,7 @@
 		"${board}/flash_blk.img && source ${loadaddr}\0" \
 	"splashpos=m,m\0" \
 	"videomode=video=ctfb:x:640,y:480,depth:18,pclk:39722,le:48,ri:16,up:33,lo:10,hs:96,vs:2,sync:0,vmode:0\0" \
-	"vidargs=video=mxsfb:640x480-16@60"
+	"vidargs=video=mxsfb:640x480M-16@60"
 
 #define CONFIG_SYS_MEMTEST_START	0x80000000
 #define CONFIG_SYS_MEMTEST_END		(CONFIG_SYS_MEMTEST_START + 0x08000000)