ath: Map New Zealand to FCC3_ETSIC

The regdomain code is used to select the correct the correct conformance
test limits (CTL) for a country. If the regdomain code isn't correctly
mapped to the actual CTL entries in EEPROM then it could happen that the
device violates the regulations. But it can also happen that the device is
then not able to be used with its full txpower on all rates.

This change itself doesn't change the selected CTL of this country and is
only required to stay in sync with the QCA mappings.

Signed-off-by: Sven Eckelmann <sven.eckelmann@openmesh.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>