drm/kms/fb: use slow work mechanism for normal hotplug also.

a) slow work is always used now for any fbcon hotplug, as its not
   a fast task and is more suited to being ran under slow work.

b) attempt to not do any fbdev changes when X is running as we'll
   just mess it up. This hooks set_par to hopefully do the changes
   once X hands control to fbdev.

This also adds the nouveau/intel hotplug support.

Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/nouveau/nouveau_fbcon.h

@@ -57,5 +57,7 @@ void nouveau_fbcon_set_suspend(struct drm_device *dev, int state);
 void nouveau_fbcon_zfill_all(struct drm_device *dev);
 void nouveau_fbcon_save_disable_accel(struct drm_device *dev);
 void nouveau_fbcon_restore_accel(struct drm_device *dev);
+
+void nouveau_fbcon_hotplug(struct drm_device *dev);
 #endif /* __NV50_FBCON_H__ */