drm/amdgpu: ih reroute for newer asics than vega20

Starting Arcturus, it supports ih reroute through mmio directly
in bare metal environment. This is also valid for newer asics
such as Aldebaran.

Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>