net/mlx5: Add balance ID support for LAG multiplane groups

net/mlx5: Add balance ID support for LAG multiplane groups

Implement balance ID support for multiplane LAG configurations. This
feature enables per-multiplane group load balancing by extending the
software system image GUID with a balance ID component.

Key implementations:
- Enable lag_per_mp_group capability when supported by hardware.
- Append load_balance_id to software system image GUID when conditions
  are met.
- Increase MLX5_SW_IMAGE_GUID_MAX_BYTES from 8 to 9 to accommodate the
  extra byte.

The balance ID is appended to the system image GUID only when both
load_balance_id and lag_per_mp_group capabilities are available, ensuring
backward compatibility while enabling enhanced LAG functionality.

This enhancement allows for more granular load balancing control in complex
multi-plane LAG deployments, improving network performance and flexibility.

Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Reviewed-by: Shay Drori <shayd@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/1761211020-925651-6-git-send-email-tariqt@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>