brcmfmac: use mfp if required from user-space

brcmfmac: use mfp if required from user-space

The struct cfg80211_connect_params indicate whether the connection
should use management frame protection (mfp). If required set the
MFP_CAPABLE flag in the firmware command. This is supported from
user-space by wpa_supplicant since v2.1.

Reviewed-by: Daniel (Deognyoun) Kim <dekim@broadcom.com>
Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>