drm/msm/dp: use scaled up mvid/nvid values

Experiments have found that scaled up values for Mvid and Nvid
close to 0x8000 while maintaining the ratio, works better for
different kinds of DP monitors. Use these scaled up values
for better interoperability with DP monitors.

Change-Id: Idfb52b2d9a0eeaa452d7376e998835112f4de61a
Signed-off-by: Ajay Singh Parmar <aparmar@codeaurora.org>