igc: Add XDP hints kfuncs for RX hash

This implements XDP hints kfunc for RX-hash (xmo_rx_hash).
The HW rss hash type is handled via mapping table.

This igc driver (default config) does L3 hashing for UDP packets
(excludes UDP src/dest ports in hash calc).  Meaning RSS hash type is
L3 based.  Tested that the igc_rss_type_num for UDP is either
IGC_RSS_TYPE_HASH_IPV4 or IGC_RSS_TYPE_HASH_IPV6.

This patch also updates AF_XDP zero-copy function igc_clean_rx_irq_zc()
to use the xdp_buff wrapper struct igc_xdp_buff.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Yoong Siang <yoong.siang.song@intel.com>
Link: https://lore.kernel.org/bpf/168182465285.616355.2701740913376314790.stgit@firesoul