gfxstream: vulkan-docs: track feature type

The newest version of Vulkan docs doesn't have this, and it
needs to be patched in.

Reviewed-by: Aaron Ruby <aruby@blackberry.com>
Acked-by: Yonggang Luo <luoyonggang@gmail.com>
Acked-by: Adam Jackson <ajax@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27246>

src/gfxstream/codegen/scripts/generator.py

@@ -355,6 +355,9 @@ class OutputGenerator:
         self.featureName = None
         """The current feature name being generated."""
 
+        self.featureType = None
+        """The current feature type being generated."""
+
         self.genOpts = None
         """The GeneratorOptions subclass instance."""
 
@@ -935,6 +938,7 @@ class OutputGenerator:
         - emit - actually write to the header only when True"""
         self.emit = emit
         self.featureName = interface.get('name')
+        self.featureType = interface.get('type')
         # If there is an additional 'protect' attribute in the feature, save it
         self.featureExtraProtect = interface.get('protect')
 
@@ -943,6 +947,7 @@ class OutputGenerator:
 
         Derived classes responsible for emitting feature"""
         self.featureName = None
+        self.featureType = None
         self.featureExtraProtect = None
 
     def genRequirements(self, name, mustBeFound = True):