brcmfmac: Use real cookie value for p2p remain on channel.

In some rare situations the wpa_supplicant can lock up on a remain
on channel command. Use actual cookies for the remain on channel
related commands and allow for additional remain on channel while
still having one set.

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