drm/msm/sde: fix ESD check scheduling issue

In the current implementation ESD check is enabled
to run when encoder enable happens. But encoder enable
also gets called for dfps change use cases. This is
causing the ESD thread not run in regular intervals.
So move the enabling of ESD check as part of CRTC
enable sequence.

Change-Id: I6fa9e9a0a6894f0a25f010ff744612216711eb85
Signed-off-by: Sandeep Panda <spanda@codeaurora.org>