net/mlx5: add VF LAG mode bonding device recognition

net/mlx5: add VF LAG mode bonding device recognition

The Mellanox NICs starting from ConnectX-5 support LAG over
NIC ports internally, implemented by the NIC firmware and hardware.
The multiport NIC presents multiple physical PCI functions (PF),
with SR-IOV multiple virtual PCI functions (VFs) might be presented.
With switchdev mode the VF representors are engaged and PFs and their
VFs are connected by internal E-Switch feature. Each PF and related VFs
have dedicated E-Switch and belong to dedicated switch domain.

If NIC ports are combined to support NIC the kernel drivers introduce
the single unified Infiniband multiport devices, and all only one
unified E-Switch with single switch domain combines master PF
all all VFs. No extra DPDK bonding device is needed.

Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
Acked-by: Matan Azrad <matan@mellanox.com>