net: microchip: vcap api: Check chains when adding a tc flower filter

This changes the way the chain information verified when adding a new tc
flower filter.

When adding a flower filter it is now checked that the filter contains a
goto action to one of the IS2 VCAP lookups, except for the last lookup
which may omit this goto action.

It is also checked if you attempt to add multiple matchall filters to
enable the same VCAP lookup.  This will be rejected.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>