igb: Add AF_XDP zero-copy Rx support

Add support for AF_XDP zero-copy receive path.

When AF_XDP zero-copy is enabled, the rx buffers are allocated from the
xsk buff pool using igb_alloc_rx_buffers_zc().

Use xsk_pool_get_rx_frame_size() to set SRRCTL rx buf size when zero-copy
is enabled.

Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@est.tech>
[Kurt: Port to v6.12 and provide napi_id for xdp_rxq_info_reg(),
       RCT, remove NETDEV_XDP_ACT_XSK_ZEROCOPY, update NTC handling,
       READ_ONCE() xsk_pool, likelyfy for XDP_REDIRECT case]
Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: George Kuruvinakunnel <george.kuruvinakunnel@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://patch.msgid.link/20250106221929.956999-6-anthony.l.nguyen@intel.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>