This adds all the attributes that are marked as mandatory for SoH in
IF-TNCCS-SOH v1.0. MS-Machine-Inventory does not contain correct data
(i.e., all version fields are just marked as inapplicable) and
MS-MachineName is hardcoded to wpa_supplicant@w1.fi for now.
Process SoH Request in SoH EAP Extension method and reply with SoH TLV. The
contents of SSoH is not yet complete (i.e., some of the required attributes
are still missing). Use of SoH is disabled by default; it can be enabled
with tnc=soh in phase1 parameter for PEAP.