fb: carminefb: trivial annotation packing color register

drivers/video/carminefb.c:171:41: warning: cast to restricted __be32

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>