PCI: Rename PCI_VC_PORT_REG1/2 to PCI_VC_PORT_CAP1/2

These are set of two capability registers, it's pretty much given that
they're registers, so reflect their purpose in the name.

Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --cc drivers/pci/vc.c
Simple merge

diff --cc drivers/vfio/pci/vfio_pci_config.c
Simple merge

diff --cc include/uapi/linux/pci_regs.h
Simple merge