ARM: S3C2410: Add S3C2410A sysdev.

Add a sysdev S3C2410A sysdev to allow the differentiation
of the S3C2410A from the S3C2410. This is needed for the
CPUFREQ code to enable the extra features and update cpu
specific information.

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