drm/i915: Allow LVDS to be on pipe A for Ironlake+

Previously we enabled this for gen4, only to have to revert it due to it
causing a large number of spurious wakeups. Try again hoping that the
hardware has become more sane in the mean time...
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/intel_lvds.c

@@ -907,6 +907,8 @@ bool intel_lvds_init(struct drm_device *dev)
 
 	intel_encoder->clone_mask = (1 << INTEL_LVDS_CLONE_BIT);
 	intel_encoder->crtc_mask = (1 << 1);
+	if (INTEL_INFO(dev)->gen >= 5)
+		intel_encoder->crtc_mask |= (1 << 0);
 	drm_encoder_helper_add(encoder, &intel_lvds_helper_funcs);
 	drm_connector_helper_add(connector, &intel_lvds_connector_helper_funcs);
 	connector->display_info.subpixel_order = SubPixelHorizontalRGB;