ionic: handle vlan id overflow

ionic: handle vlan id overflow

Add vlans to the existing rx_filter_sync mechanics currently
used for managing mac filters.

Older versions of our firmware had no enforced limits on the
number of vlans that the LIF could request, but requesting large
numbers of vlans caused issues in FW memory management, so an
arbitrary limit was added in the FW.  The FW now returns -ENOSPC
when it hits that limit, which the driver needs to handle.

Unfortunately, the FW doesn't advertise the vlan id limit,
as it does with mac filters, so the driver won't know the
limit until it bumps into it.  We'll grab the current vlan id
count and use that as the limit from there on and thus prevent
getting any more -ENOSPC errors.

Just as is done for the mac filters, the device puts the device
into promiscuous mode when -ENOSPC is seen for vlan ids, and
the driver will track the vlans that aren't synced to the FW.
When vlans are removed, the driver will retry the un-synced
vlans.  If all outstanding vlans are synced, the promiscuous
mode will be disabled.

Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>