msm: mdss: Dynamic FPS using VFP

Using Fixed fps and v_total for BW calculations, it
results in underrun if dynamic fps and v_total is used.
Dynamic FPS change should be Mutex protected for
synchronization between read/write so that multiple
processes don’t change fps at the same time. Line
count should be checked to make sure we have sufficient
lines before we start programming FPS. Do not configure
new fps when vsync timeout happens. Add support for
FIFO empty recovery.

CRs-Fixed: 651333
Change-Id: Icff48a7f85755484a321f0de26d4816f895c367e
Signed-off-by: Justin Philip <jphili@codeaurora.org>
Signed-off-by: raghavendra ambadas <rambad@codeaurora.org>