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>