msm: vidc: Reorganize bus vote module in video

Restructure the video driver apis used to calculate and
vote bus bandwidth.
1. Introduce a header having bus related info.
2. Remove the remaining dependencies with governor.
3. Remove extern api.
4. Target specific function pointer to make it scalable.

Change-Id: Ief045fac9d9df1cb3d6307d2902f9189c7f8b311
Signed-off-by: Vikash Garodia <vgarodia@codeaurora.org>