uath: add support for GCMP-128 encryption

Explicitly set the software ciphers; add support for GCMP-128.

Locally tested:

• AR5523 11abg NIC, 2/5GHz STA operation, GCMP forced in wpa_supplicant.conf

Differential Revision: https://reviews.freebsd.org/D49370
Reviewed by: bz