The wps_cred_process option can be used to configure wpa_supplicant to
send received Credential attributes for external processing over
ctrl_iface and dbus. This allows external programs to update their
configuration when WPS is used to provision new networks.
This adds support for setting of a regulatory domain to wpa_supplicant
drivers. It also adds regulatory domain setting for the nl80211 driver.
We expect an ISO / IEC 3166 alpha2 in the wpa configuration file as a
global.
