disp: msm: dsi: Add support for secondary display using firmware approach

Currently, changing panel configuration from firmware approach is present
for single display. This change adds support for secondary display using
firmware approach.

Change-Id: I8095dceed1567d8582c7473c0ac7f59c4666a200
Signed-off-by: Lipsa Rout <lrout@codeaurora.org>