drm/nouveau/bar: convert to new-style nvkm_subdev

drivers/gpu/drm/nouveau/include/nvif/device.h

drivers/gpu/drm/nouveau/include/nvkm/subdev/bar.h

drivers/gpu/drm/nouveau/nouveau_bo.c

drivers/gpu/drm/nouveau/nvkm/engine/device/base.c

drivers/gpu/drm/nouveau/nvkm/engine/device/gf100.c

drivers/gpu/drm/nouveau/nvkm/engine/device/gk104.c

drivers/gpu/drm/nouveau/nvkm/engine/device/gm100.c

drivers/gpu/drm/nouveau/nvkm/engine/device/nv50.c

drivers/gpu/drm/nouveau/nvkm/engine/fifo/gf100.c

drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c

drivers/gpu/drm/nouveau/nvkm/engine/sw/gf100.c

drivers/gpu/drm/nouveau/nvkm/engine/sw/nv50.c

drivers/gpu/drm/nouveau/nvkm/subdev/bar/Kbuild

drivers/gpu/drm/nouveau/nvkm/subdev/bar/base.c

drivers/gpu/drm/nouveau/nvkm/subdev/bar/g84.c

drivers/gpu/drm/nouveau/nvkm/subdev/bar/gf100.c

drivers/gpu/drm/nouveau/nvkm/subdev/bar/gf100.h

drivers/gpu/drm/nouveau/nvkm/subdev/bar/gk20a.c

drivers/gpu/drm/nouveau/nvkm/subdev/bar/nv50.c

drivers/gpu/drm/nouveau/nvkm/subdev/bar/nv50.h