drivers: clk: use COMMON_CLK_SAMSUNG for Samsung clock support

This patch replaces PLAT_SAMSUNG with COMMON_CLK_SAMSUNG for Samsung
common clock support. Any Samsung SoC want to use Samsung common clock
infrastructure can simply select COMMON_CLK_SAMSUNG.

CC: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Signed-off-by: Tomasz Figa <t.figa@samsung.com>