ARM: SAMSUNG: Set S3C_FB_MAX_WIN in <plat/fb.h>

Move the S3C_FB_MAX_WIN to the platform data to avoid
having to include the registers with the platform data.

Set S3C_FB_MAX_WIN to 5, which is the maximum that any
of the current hardware can do and the cost of having
it set to this for all is minimal (at least for the
platform data case), then always leave this as the maximum
for the systems supported.

Also remove the inclusion of <mach/regs-fb.h> from
the device definition in arch/arm/plat-samsung

Signed-off-by: Ben Dooks <ben-linux@fluff.org>