Fix issues with data driven split keyboards (#16457)

lib/python/qmk/info.py

@@ -550,6 +550,11 @@ def _matrix_size(info_data):
             info_data['matrix_size']['cols'] = len(info_data['matrix_pins']['cols'])
             info_data['matrix_size']['rows'] = len(info_data['matrix_pins']['rows'])
 
+        # Assumption of split common
+        if 'split' in info_data:
+            if info_data['split'].get('enabled', False):
+                info_data['matrix_size']['rows'] *= 2
+
     return info_data