disp: msm: dsi: select timing mode shared from kernel command line

If the command line timing is given, select corresponding
drm display mode as preferred mode. Select first sub mode of
that timing as preferred mode if dynamic clock or dynamic fps
is enabled.

Change-Id: I688b3bc07f79f4d014b8a7797204d3d6a873222d
Signed-off-by: Rajeev Nandan <rajeevny@codeaurora.org>