drm/amdkfd: Add spatial partitioning support in KFD

This patch introduces multi-partition support in KFD.
This patch includes:
- Support for maximum 8 spatial partitions in KFD.
- Initialize one HIQ per partition.
- Management of VMID range depending on partition mode.
- Management of doorbell aperture space between all
  partitions.
- Each partition does its own queue management, interrupt
  handling, SMI event reporting.
- IOMMU, if enabled with multiple partitions, will only work
  on first partition.
- SPM is only supported on the first partition.
- Currently, there is no support for resetting individual
  partitions. All partitions will reset together.

Signed-off-by: Mukul Joshi <mukul.joshi@amd.com>
Tested-by: Amber Lin <Amber.Lin@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>