[PATCH] Add support for high priority scheduling in amdgpu v8

[andresx7@xxxxxxxxx (Andres Rodriguez)]

Includes fixes for Alex's comments on v7.

Also includes a new patch to deal with an issue we discussed on #radeon:
[PATCH 15/26] drm/amdgpu: avoid KIQ clashing with compute or KFD

Patches missing review/ack:
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