drm/i915: rip out an unused lvds_reg variable

Somehow this has been forgotten in

commit 1974cad0ee4ce84e5cb792e49c4f0d9421e0312c
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Mon Nov 26 17:22:09 2012 +0100

    drm/i915: move is_dual_link_lvds to intel_lvds.c

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -651,12 +651,6 @@ intel_g4x_find_best_PLL(const intel_limit_t *limit, struct drm_crtc *crtc,
 	found = false;
 
 	if (intel_pipe_has_type(crtc, INTEL_OUTPUT_LVDS)) {
-		int lvds_reg;
-
-		if (HAS_PCH_SPLIT(dev))
-			lvds_reg = PCH_LVDS;
-		else
-			lvds_reg = LVDS;
 		if (intel_is_dual_link_lvds(dev))
 			clock.p2 = limit->p2.p2_fast;
 		else