msm: mdss: remove usage of DSI ctrl mutex during ESD/suspend path

The MDP control path mutex takes care of synchronizing display
suspend path and ESD thread to avoid race conditions. The DSI
OFF path is also taken care of under the MDP control path mutex.
Hence, avoid the usage of DSI ctrl mutex in ESD thread.

Change-Id: I523130bac65f9c4b736e19eb5888c83b9542ed27
Signed-off-by: Padmanabhan Komanduru <pkomandu@codeaurora.org>