ARM: S3C: Prepare s3c64xx-specific s3c-fb register definition for reuse

S5PC1xx Samsung SOC series has very similar frame buffer hardware, so a lot
of the code can be shared. Moved s3c64xx-specific s3c-fb register
definitions from mach-s3c6400 to common platform directory as regs-fb-v4.h.
The new v4 file will be common for S3C6400, S3C6410, S5PC100 and possibly
others. Some s3c64xx series specific defines (palette handling) were left
in s3c-6400/mach/regs-fb.h, because it is handled differently in S5PC1xx
series.

Signed-off-by: Pawel Osciak <p.osciak@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>