mdss: display: add spin_lock to mdss_disable_irq_nosync()

Add spin_lock to mdss_lock inside mdss_disable_irq_nosync
to avoid race condition which can cause mdss_irq to be disabled
while irq_mask bits are still set.

CRs-Fixed: 624806
Change-Id: I44074a057dff49dfc7a4d2829f3c4e599dca4a69
Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
msm: display: reduce display commit prepare waiting time

Unblock overlay_set, prepare and buffer sync ioctls when
commit thread finishes hardware programming.
Use wait_for_kickoff nstead of pan_idle for these ioctls.

Change-Id: Iefb6cbc390d2130926fdcb93688b4d92bfb26937
Signed-off-by: Ken Zhang <kenz@codeaurora.org>
Signed-off-by: Neti Ravi Kumar <ravineti@codeaurora.org>