bnxt: add page_pool support for aggregation ring when using xdp

If we are using aggregation rings with XDP enabled, allocate page
buffers for the aggregation rings from the page_pool.

Signed-off-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>