net: lan966x: Add support for XDP_TX

Extend lan966x XDP support with the action XDP_TX. In this case when the
received buffer needs to execute XDP_TX, the buffer will be moved to the
TX buffers. So a new RX buffer will be allocated.
When the TX finish with the frame, it would give back the buffer to the
page pool.

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