In PCIe r1.0, sec 5.10.2, bit 0 of the Uncorrectable Error Status, Mask,
and Severity Registers was for "Training Error." In PCIe r1.1, sec 7.10.2,
bit 0 was redefined to be "Undefined."

Rename PCI_ERR_UNC_TRAIN to PCI_ERR_UNC_UND to reflect this change.

No functional change.

[bhelgaas: changelog]
Signed-off-by: NChen, Gong <gong.chen@linux.intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>