scripts: Add generator options for extension helper

Change-Id: Ice9f1361c56de3cc342dd40a589580f4565bbc9e
diff --git a/scripts/lvl_genvk.py b/scripts/lvl_genvk.py
index eab932f..e90e0a3 100644
--- a/scripts/lvl_genvk.py
+++ b/scripts/lvl_genvk.py
@@ -379,6 +379,28 @@
             helper_file_type  = 'object_types_header')
         ]
 
+    # Helper file generator options for extension_helper.h
+    genOpts['vk_extension_helper.h'] = [
+          HelperFileOutputGenerator,
+          HelperFileOutputGeneratorOptions(
+            filename          = 'vk_extension_helper.h',
+            directory         = directory,
+            apiname           = 'vulkan',
+            profile           = None,
+            versions          = allVersions,
+            emitversions      = allVersions,
+            defaultExtensions = 'vulkan',
+            addExtensions     = addExtensions,
+            removeExtensions  = removeExtensions,
+            prefixText        = prefixStrings + vkPrefixStrings,
+            protectFeature    = False,
+            apicall           = 'VKAPI_ATTR ',
+            apientry          = 'VKAPI_CALL ',
+            apientryp         = 'VKAPI_PTR *',
+            alignFuncParam    = 48,
+            helper_file_type  = 'extension_helper_header')
+        ]
+
 
 # Generate a target based on the options in the matching genOpts{} object.
 # This is encapsulated in a function so it can be profiled and/or timed.