ARM: select COMMON_CLK_SAMSUNG for ARCH_EXYNOS and ARCH_S3C64XX

This patch selects COMMON_CLK_SAMSUNG for EXYNOS and S3C64XX SoC
and removes COMMON_CLK selection as COMMON_CLK_SAMSUNG selects it's dependency.

CC: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Signed-off-by: Tomasz Figa <t.figa@samsung.com>