hostapd: Add DUP_NETWORK global control interface command

hostapd: Add DUP_NETWORK global control interface command

This adds a new global control interface command DUP_NETWORK with the
following syntax:

DUP_NETWORK src_ifname dst_ifname param

The currently supported parameters:
  wpa
  wpa_key_mgmt
  wpa_pairwise
  rsn_pairwise
  wpa_passphrase
  wpa_psk

The specified configuration parameter is copied from the source
interface to the destination interface. The main use for this is to
allow cloning of security configuration without having to expose the
keys from the hostapd process.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>