drm/amdgpu/sriov: No need the event 3 and 4 now

As will call unload kms when initialize fail, and the unload kms will
send event 3 and 4, so don't need event 3 and 4 in device init.

Signed-off-by: Emily Deng <Emily.Deng@amd.com>
Reviewed-by: Zhan Liu <zhan.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>