ixgbe: call pcie_get_mimimum_link to check if device has enough bandwidth

This patch uses the new pcie_get_minimum_link function to perform a check to
ensure that the adapter is hooked into a slot which is capable of providing the
necessary bandwidth. This check supersedes the original method which only
checked the current pci device. The new method is capable of determining the
minimum speed and link of an entire PCI chain.

-v2-
* update the error message to include encoding loss

CC: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>