drm/amdkfd: Add topology support for CPUs

Currently, the KFD topology information is generated by parsing the CRAT
(ACPI) table. However, at present CRAT table is available only for AMD
APUs. To support CPUs on systems without a CRAT table, the KFD driver will
create a Virtual CRAT (VCRAT) table and then the existing code will parse
that table to generate topology.

Signed-off-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>