msm: mdss: dp: always set default resolution

EDID utility always lists the default resolution as part of the list
of available modes. If the client does not specify a default resolution
it can result in incorrect behavior. Ensure that the Display Port
driver always initialized with a default resolution.

CRs-Fixed: 2030915
Change-Id: Ib6c75d655e6fcbd5c792ca1aa9da6b08ba2f416e
Signed-off-by: Aravind Venkateswaran <aravindh@codeaurora.org>