ktypes/standard: disable CONFIG_MANDATORY_FILE_LOCKING

As discussed here: https://lore.kernel.org/lkml/YRcyqbpVqwwq3P6n@casper.infradead.org/

And also disabled by other distros (ref: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1940392

)

There is a push to remove mandatory file locking. By disabling this
option in our kernel types, we'll be prepared for the change.

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

ktypes/standard/standard.cfg

@@ -1115,3 +1115,5 @@ CONFIG_LIBCRC32C=y
 CONFIG_ZLIB_DEFLATE=y
 
 CONFIG_SHMEM=y
+
+# CONFIG_MANDATORY_FILE_LOCKING is not set