ath: fix dynamic user regulatory domain support

As it stands dynamic user regulatory domain support is
only possible for a few programmed regulatory domains as
a few countries do not allow for this.

The existing code however only would take advantage of
the feature if a custom world regulatory domain is used
though as that's when we clear beconing flags. We need
to lift this restriction as otherwise this feature is
pointless.

Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>