msm: kgsl: schedule the event queue after the dispatcher work queue

A race condition exists where the last retired timestamp may change
while processing the dispatcher work queue. If the next command is
a sync event that has not yet signaled a deadlock may occur.

Change-Id: I1113f2e60b8adeade65d6d979777a0aa276a172b
Signed-off-by: Jeff Boody <jboody@codeaurora.org>