msm: vidc: Change governor to assume two-stage encoding

To keep inline with firmware configuration, change the encoding mode to
two-stage, so that we appropriately vote for bandwidth.

Change-Id: I6b75798fe0ceb62e3a5489d49982351f39b3f4c6
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>