drm/amdgpu/psp: Return failure when firmware failed to load in SRIOV

In SRIOV, PSP will block incompatible firmware from loading. When this happens,
driver should be prevented from continue initialization and start cleanup.
Return failure in psp_cmd_submit_buf when firmware load failed in SRIOV.

Signed-off-by: Alice Wong <shiwei.wong@amd.com>
Reviewed-by: Sashank Saye <sashank.saye@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>