drm/i915/dsi: add support for sequence block v3 gpio for VLV

Only support North Core (NC) GPIOs for now, and assume the vlv gpio
table only has NC GPIOs for now.
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/d51c9479e8ef0b201452086870e7785928a86289.1461666263.git.jani.nikula@intel.com

drivers/gpu/drm/i915/intel_dsi_panel_vbt.c

@@ -203,8 +203,8 @@ static void vlv_exec_gpio(struct drm_i915_private *dev_priv,
 	map = &vlv_gpio_table[gpio_index];
 
 	if (dev_priv->vbt.dsi.seq_version >= 3) {
-		DRM_DEBUG_KMS("GPIO element v3 not supported\n");
-		return;
+		/* XXX: this assumes vlv_gpio_table only has NC GPIOs. */
+		port = IOSF_PORT_GPIO_NC;
 	} else {
 		if (gpio_source == 0) {
 			port = IOSF_PORT_GPIO_NC;