drm/amd: Skip not used microcode loading in SRIOV

smc, sdma, sos, ta and asd fw is not used in SRIOV. Skip them to
accelerate sw_init for navi12.

v2: skip above fw in SRIOV for vega10 and sienna_cichlid
v3: directly skip psp fw loading in SRIOV
Signed-off-by: Jingwen Chen <Jingwen.Chen2@amd.com>
Reviewed-by: Emily.Deng <Emily.Deng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>