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.

Signed-off-by: Ken Zhang <kenz@codeaurora.org>
Change-Id: Ia3f2a786b2ffb019bea19a9f00297abfc62aa00b