brcmfmac: Make p2pon module param always available.

p2pon module param is currently under define BRCMDBG. Though it is
a needed option for older versions of the wpa_supplicant which do not
support the P2P_DEVICE interface.

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>