mvpp2: add basic XDP support

Add XDP native support.
By now only XDP_DROP, XDP_PASS and XDP_REDIRECT
verdicts are supported.

Co-developed-by: Sven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: Sven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>