msm: vidc: enhance CVP usage functionality

Amend below CVP functionalities

- enable logic
- start sequence
- frame skip logic
- downscale resolution logic
- debugfs support.

Change-Id: I21ad934526c338916d130aaf3401bd89b574b4c1
Signed-off-by: Maheshwar Ajja <majja@codeaurora.org>