Assorted MOCS updates
The Xe MOCS code is heavily modelled after the equivalent i915 code, but there are a few items that are not appropriate for the Xe driver. Philippe's patch to add the MTL-specific table is also included.
As a follow-up, I'd like to rework Xe's MOCS to just use the xe_reg_sr framework. But that's a bit more invasive, so I'll save that for a future series.