mlxsw: spectrum: Add Support for erif table entries access

Implement dpipe's table ops for erif table which provide:
1. Getting the entries in the table with the associate values.
	- match on "mlxsw_meta:erif_index"
	- action on "mlxsw_meta:forwared_out"
2. Synchronize the hardware in case of enabling/disabling counters which
   mean removing erif counters from all interfaces.

Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>