ARM: S3C24XX: move common S3C2443 clock definitions to clock.h

plat-samsung/clock.h currently keeps all the SoC specific clock
declarations except the ones for S3C2443/S3C2416 which were kept in
s3c2443.h.

This patch moves them out of s3c2443.h to get rid of the header
completely later on.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>