drm/udl: Make sure to get correct endian keys from vendor descriptor

This is a port of
commit b49f184b640dcfab7ede394cf2a1ff4fe3d154f5
Author: Ben Collins <bcollins@ubuntu.com>
from udlfb to udl kms driver.

The driver was not using le16_to_cpu when reading keys from the vendor
descriptor, causing incorrect parsing. Mainly, sku_pixel_limit was not
being parsed on big-endian systems. This would result in a blank screen
on big-endian CPUs where the DL chips's max mode was smaller than the
monitor's native mode.

Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/udl/udl_main.c

@@ -61,7 +61,7 @@ static int udl_parse_vendor_descriptor(struct drm_device *dev,
 			u8 length;
 			u16 key;
 
-			key = *((u16 *) desc);
+			key = le16_to_cpu(*((u16 *) desc));
 			desc += sizeof(u16);
 			length = *desc;
 			desc++;