drm/amdgpu: disable DRIVER_ATOMIC under SRIOV

Under SRIOV, we need disable DRIVER_ATOMIC.
Otherwise, it will trigger WARN_ON at drm_universal_plane_init.

Signed-off-by: Yintian Tao <[e-mail]>
Acked-by: Alex Deucher <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c

···
 	/* enable virtual display */
 	adev->mode_info.num_crtc = 1;
 	adev->enable_virtual_display = true;
+	adev->ddev->driver->driver_features &= ~DRIVER_ATOMIC;
 	adev->cg_flags = 0;
 	adev->pg_flags = 0;
 }