net: octeontx2: Add metadata support for xdp mode

net: octeontx2: Add metadata support for xdp mode

Set metadata size building the skb from xdp_buff in octeontx2 driver.
octeontx2 driver sets xdp headroom to OTX2_HEAD_ROOM

OTX2_HEAD_ROOM	OTX2_ALIGN
OTX2_ALIGN	128

so the headroom is large enough to contain xdp_frame and xdp metadata.
Please note this patch is just compiled tested.

Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20250318-mvneta-xdp-meta-v2-4-b6075778f61f@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>