More Intel Graphics Work In Linux 5.12: Gen7 Improvements, Faster Suspend/Resume

New feature material for Linux 5.12 continues getting ready ahead of the merge window opening in February to formally kick off the cycle.

On top of the prior Intel graphics driver improvements queued up in recent weeks to DRM-Next, another batch of Intel updates were sent out this week. The latest work included with this pull includes:

- Faster suspend/resume performance by using WBINVD rather than overlapping CLFLUSH calls.

- Intel Gen7 graphics now support per-engine reset rather than just resetting the entire GPU. This should yield a better experience for the aging Gen7 graphics when encountering issues.

- Building off the recent fixes/improvements around the updated iGPU Leak mitigation handling, there is another fix in this pull. The fix is for clearing potentially malicious register state prior to executing the clear residuals security mitigation (the "iGPU Leak" mitigation).

- Interactive priority boosting is now applied to explicit fences, similar to the priority boosting done for rendering if a mode-set/page-flip is waiting on it.

- Various other fixes and code improvements.

The full list of Intel graphics changes as part of this week's batch via the pull request.