msm: ipa: fix clock issue which cause poll_mode out of sync

The pm_activate in irq_rx_schedule_poll can be in progress
and a workqueue will be started to enable NAPI. The NAPI poll and
pm_activate can happen in the same time which will cause the
poll_mode in ipa and gsi out of sync. The fix is to add the
pm_activate_sync in workqueue and make sure the clock enabled
before start NAPI.

Change-Id: Ie7ee843e83817e46f8507bb179dc8fd90b095675
Signed-off-by: Bojun Pan <bojunp@codeaurora.org>