drm/i915: Polish intel_get_lvds_encoder()

Pass dev_priv to intel_get_lvds_encoder() and polish the
implementation a bit.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190318202653.15217-2-ville.syrjala@linux.intel.com
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/i915/intel_dp.c

@@ -7073,7 +7073,7 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
 	 * eDP and LVDS bail out early in this case to prevent interfering
 	 * with an already powered-on LVDS power sequencer.
 	 */
-	if (intel_get_lvds_encoder(&dev_priv->drm)) {
+	if (intel_get_lvds_encoder(dev_priv)) {
 		WARN_ON(!(HAS_PCH_IBX(dev_priv) || HAS_PCH_CPT(dev_priv)));
 		DRM_INFO("LVDS was detected, not registering eDP\n");