crypto: msm: add pm wakeup support for qcrypto driver

Add support for holding system from suspending while an operation
is in progress (when clks are enabled).  This is done by invoking
pm_stay_awake before enabling clks (when a crypto operation is
initiated) and invoking pm_relax when crypto operation is done.

Change-Id: I5c7ceb025f6cac1b7c985fc1c308e82f851fca72
Signed-off-by: Zhen Kong <zkong@codeaurora.org>