hwdb: allow parser to expect usage of slash sign in value of property

Although in IEEE 1394 unit function list I have a plan to use slash sign
in name of property, current implementation of parser doesn't allow it.
When parsing current entries in database excluded from parser testing, we
can find usage of slash sign in name of property.

This commit adds slash sign in allow list of the parser for my
convenience.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

hwdb.d/parse_hwdb.py

@@ -101,7 +101,7 @@ def hwdb_grammar():
     matchline = (matchline_typed | matchline_general) + EOL
 
     propertyline = (White(' ', exact=1).suppress() +
-                    Combine(UDEV_TAG - '=' - Optional(Word(alphanums + '_=:@*.!-;, "'))
+                    Combine(UDEV_TAG - '=' - Optional(Word(alphanums + '_=:@*.!-;, "/'))
                             - Optional(pythonStyleComment)) +
                     EOL)
     propertycomment = White(' ', exact=1) + pythonStyleComment + EOL