net: aquantia: correctly handle macvlan and multicast coexistence

macvlan and multicast handling is now mixed up.
The explicit issue is that macvlan interface gets broken (no traffic)
after clearing MULTICAST flag on the real interface.

We now do separate logic and consider both ALLMULTI and MULTICAST
flags on the device.

Fixes: 11ba961c ("net: aquantia: Fix IFF_ALLMULTI flag functionality")
Signed-off-by: Dmitry Bogdanov <dmitry.bogdanov@aquantia.com>
Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>