build: add subcommands to kexttool

tools/kexttool/kext.py

@@ -1,10 +1,26 @@
 import yaml
 import io
 import os
+import glob
 
 class KextSource:
     __kext_info = {}
     __src_dir_path = ''
+
+
+    def scan(path):
+        result = []
+        scan_arg = os.path.join(path, '**/extension.yaml')
+
+        for filename in glob.iglob(scan_arg, recursive=True):
+            try:
+                kext_src = KextSource(filename)
+            except Exception as e:
+                continue
+
+            result.append(kext_src)
+            
+        return result
     
 
     def __init__(self, info_file):