msm: mdss: handle timeouts from pan_idle and wait_for_kickoff

mdss_fb_pan_idle and mdss_fb_wait_for_kickoff are used to hold the
current context until it is safe to proceed. Unless shutdown is going on,
these contexts are woken up by corresponding display thread responsible
for committing a frame to display. Display thread has various delays like
waiting for fences to be signalled, waiting for previous frame to finish
or waiting for a vsync etc. Under normal circumstances, these delays are
very negligible and different threads work in good harmony. However in a
heavily loaded system or some bad thread which disables interrupts for a
long time, these delays can become very large. Increase timeout to
arbitrarily derived value and add error messaging when the timeout is
observed. Remove panic from the timeout to let the system recover by
itself.

Change-Id: I58fe4c0d8b0c43998f87384035a1eacc24d7230a
Signed-off-by: Ujwal Patel <ujwalp@codeaurora.org>