ARM: SAMSUNG: Move <plat/clock.h> to plat-samsung

Move the <plat/clock.h> header to plat-samsung where it can be used by all
the platforms, and readies it for the next round of clock updates where
the clock code will be amalgamated.

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

diff --git a/arch/arm/plat-s3c/include/plat/clock.h b/arch/arm/plat-samsung/include/plat/clock.h
similarity index 100%
rename from arch/arm/plat-s3c/include/plat/clock.h
rename to arch/arm/plat-samsung/include/plat/clock.h