EAP-pwd peer: Configurable set of groups with reduced default

EAP-pwd peer: Configurable set of groups with reduced default

Make the EAP-pwd peer use same default set of allowed groups as the SAE
implementation in wpa_supplicant uses, i.e., the groups 19-21 using NIST
curves P-256, P-384, and P-521. Previously, all groups that were
supported by the crypto library were allowed. In practice, this change
disables use of the Brainpool curves (groups 28-30) with recent OpenSSL
versions.

The default set of groups can be overridden with a new phase1 network
profile parameter, eap_pwd_groups=<list of allowed ranges>. For example,
phase1="eap_pwd_groups=0-65535" would restore previous behavior of
allowing all implemented groups to be used while eap_pwd_groups=19,20
would enable only the groups using NIST curves P-256 and P-384 to be
used.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>