mdss: use a nonthreaded interrupt

Signed-off-by: Iliyan Malchev <malchev@google.com>
(cherry picked from commit 0a1f6b2fc7ab80b8d0daf1ed77779c2d2b62e414)

Change-Id: Iac67e9331ac7f9df71c9b1296c405eaa2145af90