disp: msm: dsi: Add support to enable LP11 insertion feature

Some panels may require that the DSI link returns to the low-power
stop state (LP11) after transmission of every line. If a panel
requires that the DSI link returns to LP11, apply the LP11
insertion between lines feature.

This change adds support to
 - Disable the command mdp burst mode
 - Enable mdp idle ctrl
 - Program the No. of dsi pclk cycles of idle time to
   insert between command mode mdp packets. The idle time
   must be long enough to cover the time link takes to
   switch between HS to LP11 mode.

Change-Id: Ie718d334f05ce6c1ecd1a05b379bbbe18dec6330
Signed-off-by: Ritesh Kumar <riteshk@codeaurora.org>