brcmfmac: fix reception of P2P probe requests on P2P_DEVICE interface

The probe requests received on P2P_DEVICE interface were not sent
to wpa_supplicant, which makes the device not discoverable by peers.

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>