msm: camera: Error handling for optional clock

Add error check for the optional clock in order to restrict
further operation related to that clock. Also, Change/update log
level and log place to identify/avoid misread of log.

Change-Id: Ia0e1c7b17b487bdfb377f8d71d9d426078cdc7a0
Signed-off-by: Jigarkumar Zala <jzala@codeaurora.org>