crypto: msm: Refactor/clean-up clock code

Add clk enable/disable and init/deinit APIs.
These APIs will be used in future to allow clk scaling and
gating by clients.

Change-Id: I08503972b9ed77633e14d81711aa92c61df7a0ad
Signed-off-by: Mona Hossain <mhossain@codeaurora.org>