[RFC] Prepare to add more Samsung S3C CPUs to barebox

[Juergen Beisert]

This patch series tries to make the current Samsung S3C24XX CPU and platform
support more generic to be able to add Samsung's more recent S3C CPUs (S3C64XX
for example). Some drivers can be shared between members in the S3C family of
processors, so the drivers get a s3c in their names to reflect it. But some
parts stick to their processor. To avoid an ifdef hell, I moved these parts
into separte files.

Comments are welcome.