msm: mdss: fix fps for different interfaces

Different interfaces uses different formats for fps. Also, for
the same interface, fps format may change based on the use case.
Provide correct fps format for all uses cases to support dynamic
fps change using pixel clock change or porch change and clock
and bandwidth calculations.

Change-Id: Ifd1a92bd53a106f507c986052f63c671497ede0e
Signed-off-by: Ajay Singh Parmar <aparmar@codeaurora.org>
Signed-off-by: Ray Zhang <rayz@codeaurora.org>