disp: msm: dsi: add panel mode restriction for DFPS and RFI

Add this change to ensure that DFPS and RFI happen in the
same panel mode for avoiding unexpected panel mode switch.

Change-Id: I4296a02693aacf4813d4bdd572e6d21a155cf746
Signed-off-by: Lei Chen <chenlei@codeaurora.org>