drm/i915: Disable LPT-H VGA dotclock during crtc disable

Currently we leave the LPT-H VGA dotclock running after turning
the pipe/fdi/port/etc. Properly disable the VGA dotclock as
specified in the modeset sequence.

v2: Fix commit message typo (Paulo)
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449260534-14551-1-git-send-email-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/intel_display.c

@@ -5176,6 +5176,7 @@ static void haswell_crtc_disable(struct drm_crtc *crtc)
 
 	if (intel_crtc->config->has_pch_encoder) {
 		lpt_disable_pch_transcoder(dev_priv);
+		lpt_disable_iclkip(dev_priv);
 		intel_ddi_fdi_disable(crtc);
 
 		intel_set_pch_fifo_underrun_reporting(dev_priv, TRANSCODER_A,