mm-video: vdec: Set frame rate if computed fps is more than existing fps

- In some scenarios, low fps value is set to video driver
  which is causing frame drops.
- Set frame rate to driver only when computed frame rate is
  more than existing frame rate value.

Change-Id: Ic723d5a35a8709d57b5ff4877ebc9e6ae9aa626a
CRs-Fixed: 498003
1 file changed