Include peer certificate always in EAP events

Include peer certificate always in EAP events

This makes it easier for upper layer applications to get information
regarding the server certificate without having to use a special
certificate probing connection. This provides both the SHA256 hash of
the certificate (to be used with ca_cert="hash://server/sha256/<hash>",
if desired) and the full DER encoded X.509 certificate so that upper
layer applications can parse and display the certificate easily or
extract fields from it for purposes like configuring an altsubject_match
or domain_suffix_match.

The old behavior can be configured by adding cert_in_cb=0 to
wpa_supplicant configuration file.

Signed-off-by: Jouni Malinen <j@w1.fi>