msm: ipa: Fix to system suspend due to missing wakelock

There is a possibility that wakelock is not acquired when
polling state is set and we allow system to go to suspend.
Make a change to acquire/release the wakelock based on the
polling state to not allow system to go to suspend.

Change-Id: Iec4e7511e9a03b4f9911b280ce4ddc0e913b5185
Acked-by: Chaitanya Pratapa <cpratapa@qti.qualcomm.com>
Signed-off-by: Ravinder Konka <rkonka@codeaurora.org>