If enabled, cross connection allows GO to forward IPv4 packets
using masquerading NAT from the P2P clients in the group to an
uplink WLAN connection. This is disabled by default and can be
enabled with "wpa_cli p2p_set cross_connect 1" on the P2P device
interface.
For now, this applies to the test command that can be used to set
periodic NoA (p2p_set noa). The value are stored and periodic NoA
is enabled whenever there are no non-P2P STAs connected to the GO.
While this is not strictly speaking required by the P2P specification
for a not-P2P Managed Device, this can provide useful information for
the P2P manager AP and may be needed to pass certification tests.