net/mlx5: Report PCIe link properties with pcie_print_link_status()

Use pcie_print_link_status() to report PCIe link speed and possible
limitations.

Signed-off-by: Tal Gilboa <talgi@mellanox.com>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>