layers: Finish add support to validation for VK_KHR_display extension

Swapchain, object_tracker and unique_objects now intercept and perform
validation checks for this extension.
Change-Id: I2e78d1dc516103de165ef83b99665eaad05b73d9
diff --git a/vk_helper.py b/vk_helper.py
index dc49b0f..c55607d 100755
--- a/vk_helper.py
+++ b/vk_helper.py
@@ -1571,6 +1571,9 @@
         for m in self.struct_dict[s]:
             if self.struct_dict[s][m]['ptr']:
                 return True
+        inclusions = ['VkDisplayPlanePropertiesKHR', 'VkDisplayModePropertiesKHR', 'VkDisplayPropertiesKHR']
+        if s in inclusions:
+            return True
         return False
 
     def _generateSafeStructHeader(self):