disp: msm: sde: cancel delayed work items during TUI transition

Delayed work items may touch HW registers. If these work items
run while HW is not owned by this VM it will lead to invalid
access. This happens in video mode as HAL does not disable idle
power-collapse in this mode. It can also happen with ESD status
if lastclose or TUI transition failure occurs.

Although there is a contract with user mode to turn off certain
features, kernel cannot rely on it to always do the right thing.
Prevent potential crashes from certain corner cases by cancelling
all delayed work items when the HW ownership is transferred.

Change-Id: I08da17f2ce72bf2fddf71924c3e8edd2e2715be8
Signed-off-by: Steve Cohen <cohens@codeaurora.org>