drm/amdgpu: Add NPS switch support for GC 9.4.3

Add dynamic NPS switch support for GC 9.4.3 variants. Only GC v9.4.3 and
GC v9.4.4 currently support this. NPS switch is only supported if an SOC
supports multiple NPS modes.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com>
Reviewed-by: Feifei Xu <Feifei.Xu@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>