Use remove-advertising-clause script to edit BSD licenses

This edits licenses held by Berkeley and NetBSD, both of which
have removed the advertising requirement from their licenses.

Signed-off-by: Keith Packard <keithp@keithp.com>

mkdep

@@ -6,7 +6,7 @@
 # Redistribution and use in source and binary forms are permitted
 # provided that the above copyright notice and this paragraph are
 # duplicated in all such forms and that any documentation,
-# advertising materials, and other materials related to such
+# and/or other materials related to such
 # distribution and use acknowledge that the software was developed
 # by the University of California, Berkeley.  The name of the
 # University may not be used to endorse or promote products derived