msm: camera_v2: handle the error value returned during get clock

currently only NULL pointer check is used to validate the return
value from clk_get, this change to handle all the failures.

Change-Id: Icd8b7e33d0f235a7c5dde2307972a594908e6a60
Signed-off-by: Srikanth Uyyala <suyyala@codeaurora.org>