brcmfmac: support 4-way handshake offloading for WPA/WPA2-PSK

The firmware may have supplicant code built-in. This is detected
by the driver and indicated in the wiphy features flags. User-space
can use this flag to determine whether or not to provide the
pre-shared key material in the nl80211 CONNECT command.

Reviewed-by: Gautam (Gautam Kumar) Shukla <gautams@broadcom.com>
Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>