msm-fb: display: double the lvds pixel clock for dual lvds

Lower MDP clock causing the underrun issues on dtv boards.
To arrive at correct mdp clock pixel clock needs to be
doubled for LVDS DUAL lane panel case

Change-Id: I202f0d16896f88090a9f8407e067a31cc47eb4ea
Signed-off-by: Nagamalleswararao Ganji <nganji@codeaurora.org>