[Feature]: AV1 decode support in media-driver without any kernels built

### What Feature?

AV1 decode is currently exposed in vainfo on supported HW, but the decoding itself fails if the media-driver is built without any kernels (neither free nor non-free), supposedly because the required filmgrain kernel for AV1 decode.

Would it be possible to implement some fallback path so the driver makes the decoding at least partially on GPU on supported hardware even without any kernels built in?

I can add ffmpeg verbose log once I get to the HW that supports AV1.

Thanks!

### What's the usage scenario would be benifited?

Playback, Web browser

### What impacted?

_No response_

### Do you want to contribute a patch to develop this feature?

None