wifi: cfg80211: add support for EPPKE Authentication Protocol

wifi: cfg80211: add support for EPPKE Authentication Protocol

Add an extended feature flag NL80211_EXT_FEATURE_EPPKE to allow a
driver to indicate support for the Enhanced Privacy Protection Key
Exchange (EPPKE) authentication protocol in non-AP STA mode, as
defined in "IEEE P802.11bi/D3.0, 12.16.9".

In case of SME in userspace, the Authentication frame body is prepared
in userspace while the driver finalizes the Authentication frame once
it receives the required fields and elements. The driver indicates
support for EPPKE using the extended feature flag so that userspace
can initiate EPPKE authentication.

When the feature flag is set, process EPPKE Authentication frames from
userspace in non-AP STA mode. If the flag is not set, reject EPPKE
Authentication frames.

Define a new authentication type NL80211_AUTHTYPE_EPPKE for EPPKE.

Signed-off-by: Ainy Kumari <ainy.kumari@oss.qualcomm.com>
Co-developed-by: Kavita Kavita <kavita.kavita@oss.qualcomm.com>
Signed-off-by: Kavita Kavita <kavita.kavita@oss.qualcomm.com>
Link: https://patch.msgid.link/20260114111900.2196941-2-kavita.kavita@oss.qualcomm.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>