s3c2410fb: byte ordering fixes

This patch sets correct bits related to the byte ordering of the
framebuffer.  This was tested on little endian kernel only.  The big endian
kernel may require different settings.

The patch also adds 32 bpp mode which is called 24 bpp by Samsung.  One
pixel takes 32 bits but only 24 bits are used in this mode.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>