mm-video-v4l2: vidc: Add support for dynamic debug logging

- Add system property for setting the debug level
- Add common macros for vdec, venc for debug logs

Change-Id: Ib20d5e5890cc90c2570ba5bda6f6805c32d4a397
CRs-Fixed: 525571
Signed-off-by: Hieu Phan <aznrice2k4@gmail.com>