msm: mdss: Support command line argument parsing in mdp3

Support kernel command line argument parsing in mdp3
driver to get the preferred panel set by user or LK
over panel selected by target dtsi file. MDP3 provides
this panel information to dsi driver to configure the
user selected panel.

Change-Id: I80025d22dbab42a349bc294a9d080516682555c3
Signed-off-by: Dhaval Patel <pdhaval@codeaurora.org>