msm: mdss: configure DSI PHY regulator when coming out of idle collapse

In command mode static screen usecase if DSI PHY was clamped and
then MDSS was reset by power collapsing it, in that case reconfigure
DSI PHY regulator while coming out of power collapse. This will avoid
DSI PHY stuck issue when there are two independent displays running.

Change-Id: I6c33244c332d97522b66cbb9191fce0a268bf9f4
Signed-off-by: Sandeep Panda <spanda@codeaurora.org>