The RGB444 format swapped the red and blue components, fix this.

Rather than making a new BGR444 format (as I proposed initially), Jon prefers
to just fix this and return the colors in the right order. I think that makes
sense in this case.

Since the RGB444 pixel format is deprecated due to the ambiguous specification
of the alpha component we use the XRGB444 pixel format instead (specified as having
no alpha channel).
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>