drm/amdgpu: Add Runtime Bad Page message definitions for VFs

Currently VFs rely on poison consumption interrupt from HW
to kick off the bad page retirement process. Part of this process
includes a VF reset.

This patch adds the following:

1) Host Bad Pages notification message.
2) Guest request bad pages message.

When combined, VFs are able to reserve the pages early, and potentially
avoid future poison consumption that will disrupt user services
from consequent FLR.

Reviewed-by: Shravan Kumar Gande <Shravankumar.Gande@amd.com>
Signed-off-by: Victor Skvortsov <victor.skvortsov@amd.com>
Signed-off-by: Ellen Pan <yunru.pan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>