net: lan966x: Update rxq memory model

By default the rxq memory model is MEM_TYPE_PAGE_SHARED but to be able
to reuse pages on the TX side, when the XDP action XDP_TX it is required
to update the memory model to PAGE_POOL.

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