msm: mdss: fix potential deadlock with ulps work thread

Do not check if the clocks are on when sending the ULPS event from
the worker thread. This check is not needed since the work is only
scheduled after the clocks are turned off and would be cancelled
anyway when the clocks are turned on if it is pending. Removing this
unnecessary check avoids acquiring a shared lock which can potentially
lead to a deadlock.

Change-Id: Ib9760221f044dded50a38a32b59d0158c2f6b50e
Signed-off-by: Aravind Venkateswaran <aravindh@codeaurora.org>