drm/nouveau: create function for "dealing" with gpu lockup

It's mostly a cleanup, but in nv50_fbcon_accel_init gpu lockup
message was printed, but HWACCEL_DISBALED flag was not set.

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_fbcon.h

@@ -43,5 +43,6 @@ void nouveau_fbcon_zfill(struct drm_device *dev);
 int nv04_fbcon_accel_init(struct fb_info *info);
 int nv50_fbcon_accel_init(struct fb_info *info);
 
+void nouveau_fbcon_gpu_lockup(struct fb_info *info);
 #endif /* __NV50_FBCON_H__ */