ifconfig: decode 256 bit CCM/GCM ciphers and 256 bit 802.1x/none keymgmt
- add AES-GCM-256 and AES-CCM-256 ciphers
- add WPA-PSK-SHA256 and UNSPEC-SHA256 key management
This allows them to show in ifconfig -v wlan0 list scan, eg
RSN<v1 mc:AES-GCMP-256 uc:AES-CCMP-256+AES-GCMP-256 km:8021X-PSK+8021X-PSK-256>
Differential Revision: https://reviews.freebsd.org/D49481
Reviewed by: thj