drm/amdgpu: load sdma ucode in the guest machine

[why]
User mode driver need to check the sdma ucode version to
see whether the sdma engine supports a new type of PM4 packet.
In SRIOV, sdma is loaded by the host. And, there is no way
to check the sdma ucode version of CHIP_NAVI12 and
CHIP_SIENNA_CICHLID of the host in the guest machine.

[how]
Load the sdma ucode for CHIP_NAVI12 and CHIP_SIENNA_CICHLID
in the guest machine.

Signed-off-by: YuanShang <YuanShang.Mao@amd.com>
Reviewed-By: Horace Chen <horace.chen@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>