net: ti: icssg-prueth: Add Multicast Filtering support for VLAN in MAC mode

net: ti: icssg-prueth: Add Multicast Filtering support for VLAN in MAC mode

Add multicast filtering support for VLAN interfaces in dual EMAC mode
for ICSSG driver.

The driver uses vlan_for_each() API to get the list of available
vlans. The driver then sync mc addr of vlan interface with a locally
mainatined list emac->vlan_mcast_list[vid] using __hw_addr_sync_multiple()
API.

__hw_addr_sync_multiple() is used instead of __hw_addr_sync() to sync
vdev->mc with local list because the sync_cnt for addresses in vdev->mc
will already be set by the vlan_dev_set_rx_mode() [net/8021q/vlan_dev.c]
and __hw_addr_sync() only syncs when the sync_cnt == 0. Whereas
__hw_addr_sync_multiple() can sync addresses even if sync_cnt is not 0.
Export __hw_addr_sync_multiple() so that driver can use it.

Once the local list is synced, driver calls __hw_addr_sync_dev() with
the local list, vdev, sync and unsync callbacks.

__hw_addr_sync_dev() is used with the local maintained list as the list
to synchronize instead of using __dev_mc_sync() on vdev because
__dev_mc_sync() on vdev will call __hw_addr_sync_dev() on vdev->mc and
sync_cnt for addresses in vdev->mc will already be set by the
vlan_dev_set_rx_mode() [net/8021q/vlan_dev.c] and __hw_addr_sync_dev()
only syncs if the sync_cnt of addresses in the list (vdev->mc in this case)
is 0. Whereas __hw_addr_sync_dev() on local list will work fine as the
sync_cnt for addresses in the local list will still be 0.

Based on change in addresses in the local list, sync / unsync callbacks
are invoked. In the sync / unsync API in driver, based on whether the ndev
is vlan or not, driver passes appropriate vid to FDB helper functions.

Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>