v4l2codecs: h264: Improve ABI check and fix rk3399 support
This moves the ABI check to the registration, so we don't expose decoders with the wrong ABI or that are just broken somehow. It also makes few enhancement:
- Handle missing, but required controls
- Prints the controls macro name instead of id
This should fix RK3399 support with a currently release minor regression in the Hantro driver that cause errors.
@tpm this is a bug fix for Pinebook users notably. There is a regression in Linux that have made 2 releases, and which makes gstreamer fail to decode H.264. I leave it to you to decide to pick it now, otherwise we'll get that in 1.20.1.