drm/radeon/kms: add support for interrupts on SI

This is mostly identical to evergreen/ni, however
there are some additional fields in the IV vector
for RINGID and VMID.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
3 files changed