remove unnecessary include

This was merged with core/device.h in an earlier commit, but somehow
never got removed.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/include/nvkm/engine/device.h

-#ifndef __NOUVEAU_SUBDEV_DEVICE_H__
-#define __NOUVEAU_SUBDEV_DEVICE_H__
-
-#include <core/device.h>
-
-struct platform_device;
-
-enum nv_bus_type {
-	NOUVEAU_BUS_PCI,
-	NOUVEAU_BUS_PLATFORM,
-};
-
-#define nouveau_device_create(p,t,n,s,c,d,u)                                   \
-	nouveau_device_create_((void *)(p), (t), (n), (s), (c), (d),           \
-			       sizeof(**u), (void **)u)
-
-int  nouveau_device_create_(void *, enum nv_bus_type type, u64 name,
-			    const char *sname, const char *cfg, const char *dbg,
-			    int, void **);
-
-int nv04_identify(struct nouveau_device *);
-int nv10_identify(struct nouveau_device *);
-int nv20_identify(struct nouveau_device *);
-int nv30_identify(struct nouveau_device *);
-int nv40_identify(struct nouveau_device *);
-int nv50_identify(struct nouveau_device *);
-int nvc0_identify(struct nouveau_device *);
-int nve0_identify(struct nouveau_device *);
-int gm100_identify(struct nouveau_device *);
-#endif