drm/nvc0,nvc4/mc: handle 0xc0's "special" msi rearm

v2. updated to cover GF104, as per information provided by NVIDIA.

Reported-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --cc drivers/gpu/drm/nouveau/Makefile
Simple merge

diff --cc drivers/gpu/drm/nouveau/core/engine/device/nv40.c
Simple merge

diff --cc drivers/gpu/drm/nouveau/core/engine/device/nvc0.c
Simple merge

diff --cc drivers/gpu/drm/nouveau/core/engine/device/nve0.c
Simple merge

diff --cc drivers/gpu/drm/nouveau/core/include/subdev/mc.h
Simple merge

diff --cc drivers/gpu/drm/nouveau/core/subdev/mc/base.c
Simple merge

diff --cc drivers/gpu/drm/nouveau/core/subdev/mc/nv04.h
Simple merge

diff --cc drivers/gpu/drm/nouveau/core/subdev/mc/nv40.c
Simple merge

diff --cc drivers/gpu/drm/nouveau/core/subdev/mc/nv44.c
Simple merge

diff --cc drivers/gpu/drm/nouveau/core/subdev/mc/nv50.c
Simple merge

diff --cc drivers/gpu/drm/nouveau/core/subdev/mc/nv98.c
Simple merge

diff --cc drivers/gpu/drm/nouveau/core/subdev/mc/nvc0.c
Simple merge

diff --cc drivers/gpu/drm/nouveau/core/subdev/mc/nvc3.c
Simple merge