This is useful in cases where we connect to a slot at Gen3, but the slot
is behind a bus which only connected at Gen2. This generally only
happens when a PCIe switch is in the sequence of devices, and can be
very confusing when you see slow performance with no obvious cause.

I am aware this patch has a few lines that break 80 characters, but
there does not seem to be a readable way to format them to less than 80
characters. Suggestions welcome.
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NKrishneil Singh <krishneil.k.singh@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>