net/mlx5e: Support XDP target xmit with dummy program

net/mlx5e: Support XDP target xmit with dummy program

Save per-channel resources in default, in device and host memory.

As no better API exist, make the XDP-redirect-target SQ available by
loading a dummy XDP program.

This improves the latency of interface up/down operations when feature
is disabled.

Perf numbers:
NIC: Connect-X7.
Setup: 248 channels, default mtu and rx/tx ring sizes.

Interface up + down:
Before: 2.246 secs
After:  1.798 secs (-0.448 sec)

Saves ~1.8 msec per channel.

Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: William Tu <witu@nvidia.com>
Link: https://patch.msgid.link/1764497617-1326331-3-git-send-email-tariqt@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>