MAGETWO-57420: Backport of MAGETWO-54320: Category page showing old price -indexer to 2.1

- back porting commits from ticket MAGETWO-55055: Tier price doesn't work correctly with FPC for 2.1

Author: cpartica

app/code/Magento/Catalog/Pricing/Render/FinalPriceBox.php

@@ -128,4 +128,16 @@ public function getCacheKey()
     {
          return parent::getCacheKey() . ($this->getData('list_category_page') ? '-list-category-page': '');
     }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @return array
+     */
+    public function getCacheKeyInfo()
+    {
+        $cacheKeys = parent::getCacheKeyInfo();
+        $cacheKeys['display_minimal_price'] = $this->getDisplayMinimalPrice();
+        return $cacheKeys;
+    }
 }