brcmfmac: Update tracelogging for multiple netdevs.

When supporting multiple netdevs it is usefull to log idx in netdev
related functions. This will be used for features like P2P.

Reviewed-by: Arend Van Spriel <arend@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>