Add the `sae_check_mfp` global option to limit SAE when PMF will
not be selected for the connection.
With this option SAE is avoided when the hardware is not capable
of PMF due to missing ciphers.
With this option SAE is avoided on capable hardware when the AP
does not enable PMF.
Allows falling back to PSK on drivers with the
WPA_DRIVER_FLAGS_SAE capability but do not support the BIP cipher
necessary for PMF. This enables configurations that can fall back
to WPA-PSK and avoid problems associating with APs configured
with `sae_require_mfp=1`.
Useful when `pmf=1` and `sae_check_mfp=1` are enabled and networks
are configured with ieee80211w=3 (default) and key_mgmt="WPA-PSK SAE".
In this configuration if the device is unable to use PMF due to
lacking BIP group ciphers it will avoid SAE and fallback to
WPA-PSK for that connection.
Signed-off-by: Jeffery Miller <jefferymiller@google.com>