msm: mdss: hdmi: get vic from cmdline in case hdmi is primary

In case of HDMI is primary, get the default VIC (Video Identification
Code) from the command line to configure the display pipeline with this
resolution data for continuous splash screen.

Change-Id: I96325045f4af0712d2f68fadf190edcf6d815841
Signed-off-by: Ajay Singh Parmar <aparmar@codeaurora.org>