msm: mdss: add support for different panel formats

Some panels have different color format requirement such as
RGB666 for EDP Panel. Add logic to detect panel resolution
based on panel bpp set by panel driver.

Change-Id: I4cad59033b8b4f807c2ed38b00451aab89737bb7
Signed-off-by: Asaf Penso <apenso@codeaurora.org>
Signed-off-by: Adrian Salido-Moreno <adrianm@codeaurora.org>