drm/i915: Remove dead KMS encoder save/restore code.

This was brought over from UMS, and used for a while until we decided
that drm_helper_resume_force_mode was easier and more reliable, since
it didn't require duplicating all the code deleted here.  We just
forgot to delete all that junk for a while.

drivers/gpu/drm/i915/dvo.h

@@ -69,16 +69,6 @@ struct intel_dvo_dev_ops {
 	 */
 	void (*dpms)(struct intel_dvo_device *dvo, int mode);
 
-	/*
-	 * Saves the output's state for restoration on VT switch.
-	 */
-	void (*save)(struct intel_dvo_device *dvo);
-
-	/*
-	 * Restore's the output's state at VT switch.
-	 */
-	void (*restore)(struct intel_dvo_device *dvo);
-
 	/*
 	 * Callback for testing a video mode for a given output.
 	 *