net: bridge: convert nf call options to bits

No functional change, convert of nf_call_[ip|ip6|arp]tables to bits.

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>