drm/nv84: add support for PMPEG

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

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

diff --cc drivers/gpu/drm/nouveau/nouveau_drv.h
Simple merge

diff --cc drivers/gpu/drm/nouveau/nouveau_state.c
Simple merge

diff --cc drivers/gpu/drm/nouveau/nv84_mpeg.c
Simple merge