serial: msm_serial_hs: Move clk count voting out of runtime callbacks

Don't modify the ref count variable clk count inside the runtime callbacks.
Doing so could result in a case where the driver might end up calling a put
twice on the runtime object. The resulting imbalance will leave the runtime
state for the device in a bad state.

Change-Id: I34989768811b23762c4afe3e33e229ffa3f1db17
Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>