clk: clk-s2mps11: Add support for clocks in S5M8767 MFD

Since clock operation within S2MPS11 and S5M8767 are similar, we can
support both the devices within a single driver.

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Reviewed-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>