octeontx2-pf: Add AF_XDP non-zero copy support

Set xdp rx ring memory type as MEM_TYPE_PAGE_POOL for
af-xdp to work. This is needed since xdp_return_frame
internally will use page pools.

Fixes: 06059a1a ("octeontx2-pf: Add XDP support to netdev PF")
Signed-off-by: Suman Ghosh <sumang@marvell.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>