drm/amdkfd: Record vmid pasid mapping in the driver for non HWS mode

This makes possible the vmid pasid mapping query through software.

Signed-off-by: Yong Zhao <Yong.Zhao@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>