msm: mdss: Reset hardware cursor flag on suspend

Reset hardware cursor enable flag while going
to suspend as cursor address doesn't remain
valid after iommu detaching which create
iommu page fault after resume.

Change-Id: I2fd484de72b62f39cdeaee025995afc975b3ba6e
Signed-off-by: Pawan Kumar <pavaku@codeaurora.org>