drm/msm/sde: add support for hw recovery event notification

Add support to provide hardware recovery event notification
to registered clients. It supports three events: capture, reset
and sucecess. Client can capture the debug log when it receives
"capture" event. It can hard reset the mdss core by turning off
all displays when it receives "reset" event. sde drm driver
provides "success" notification when recovery is successful.

Change-Id: Ieeb0fbf3ca6961e7056b9c909a63170cdd415751
Signed-off-by: Abhijit Kulkarni <kabhijit@codeaurora.org>
Signed-off-by: Prabhanjan Kandula <pkandula@codeaurora.org>