clk: qcom: cpu-sdm: Add cpu clock driver for SDM

Add support for CPU clock driver for scaling of cpu
clocks on qm215/sdm targets.

Change-Id: I9ab83b02052ab9b3e4342bc72380df799fb86976
Signed-off-by: Saurabh Sahu <sausah@codeaurora.org>
Signed-off-by: Chetan C R <cchinnad@codeaurora.org>