drm/msm/dp: abort before going to suspend

During resume, DP uses AUX to perform various functionalities
like DPCD/EDID read or link training etc. This involves other
hardware modules as well like USB and Charger. In a situation
like continuous suspend/resume, while DP is processing resume,
suspend can trigger resulting in dependent hardware modules
to go to sleep. As AUX communication is hardware interrupt
based, this can result in unstable system.

Abort all functionalities before going to suspend to
avoid unnecessary AUX and other functionality failures.

CRs-Fixed: 2446337
Change-Id: Id52d408270232adf7258a7eb064ee969eba4be71
Signed-off-by: Ajay Singh Parmar <aparmar@codeaurora.org>
Signed-off-by: Sankeerth Billakanti <sbillaka@codeaurora.org>