msm: display: increase fence timeout

Increase timeout value to 900ms to allow
gfx engine to render longer.
When sync_fence_wait fails, need not put fence as
it will be handled outside the loop.

Change-Id: Id4caff55c9f99c48e5f87a85d30fe4c8c0cd65e7
Signed-off-by: Ken Zhang <kenz@codeaurora.org>