msm: mdss: handle mdp busy timeout in DSI host driver

If the wait for MDP to be idle times out while sending a DCS command, do
not queue the commands and return early. This ensures that we do not
attempt to queue commands when the panel may be unresponsive,
such as the case of an ESD attack.

Change-Id: Ia449cf2becc674c62050e60c1cf3646fe9f489bd
Signed-off-by: Aravind Venkateswaran <aravindh@codeaurora.org>
Signed-off-by: Raghavendra Ambadas <rambad@codeaurora.org>
Signed-off-by: Bharat Pawar <bpawar@codeaurora.org>
Signed-off-by: Nirmal Abraham <nabrah@codeaurora.org>