disp: msm: sde: use local_clock in sde event log

The display driver uses ktime_to_us to timestamp the messages
in the sde event log. But the kernel logs use local_clock to
timestamp the messages. Using same timestamp routine in sde event
log helps to correlate the messages from both the logs
for debug purpose.

Change-Id: Id94e03ba21f82e2162e4ef4290c10d2d09110d4c
Signed-off-by: Lakshmi Narayana Kalavala <lkalaval@codeaurora.org>