brcmfmac: Inform p2p module about p2pon through API

When the p2pon module param is used then p2p attach will initialize
p2p device iface in the firmware, but it is doing that by checking
data. It is cleaner to pass the p2pon information to p2p by API.
This information is also needed for other patch.

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: Kalle Valo <kvalo@codeaurora.org>