[Feature deprecation]: remove FEI support of gen9 and gen8

### What Feature?

FEI(flexible encode infrastructure) is a feature which expose AVC intermedia stage, then customer have chance to implement their special algorithm .
it is base one gen9 and gen8 VME path. and is complex, and no any change in past 3 years.
so, deprecate it , if someone need it , they could use release before 2025 Q1.

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

Transcode for media delivery

### What impacted?

anyone who are using FEI on gen9 (such as SKL) and gen8 (BDW)

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

None