Use bitrev8 for nvidiafb, rivafb, and tgafb drivers

Cc: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>