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

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

Change-Id: I275cb4717c675baf528e05c50058f2c6b0025011
Signed-off-by: E V Ravi <evenka@codeaurora.org>
Signed-off-by: Sumalatha Malothu <smalot@codeaurora.org>