marimba-tsadc: Move to new clk_prepare/unprepare API.

The MSM clock driver is moving to the upstream prepare/unprepare
APIs. Use these new set of APIs instead of the current
enable/disable APIs.

Change-Id: Ib3ca1050d9002d92a4d719984cc61a0ea29f8930
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>