WPS: Add mechanism for indicating non-standard WPS errors

WPS: Add mechanism for indicating non-standard WPS errors

Previously, only the Configuration Error values were indicated in
WPS-FAIL events. Since those values are defined in the specification
it is not feasible to extend them for indicating other errors. Add
a new error indication value that is internal to wpa_supplicant and
hostapd to allow other errors to be indicated.

Use the new mechanism to indicate if negotiation fails because of
WEP or TKIP-only configurations being disallows by WPS 2.0.