net: microchip: sparx5: Adding initial VCAP API support

This provides the initial VCAP API framework and Sparx5 specific VCAP
implementation.

When the Sparx5 Switchdev driver is initialized it will also initialize its
VCAP module, and this hooks up the concrete Sparx5 VCAP model to the VCAP
API, so that the VCAP API knows what VCAP instances are available.

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