Define AFC vendor commands and events

Define AFC vendor commands and events

Wi-Fi Alliance specification for Automated Frequency Coordination (AFC)
system ensures that the Standard Power Wi-Fi devices can operate in 6
GHz spectrum under favorable conditions, without any interference with
the incumbent devices.

Add support for vendor command/events and corresponding
attributes to define the interface for exchanging AFC requests and
responses between the driver and a userspace application.

Signed-off-by: Jouni Malinen <quic_jouni@quicinc.com>