PCI: Make pcie_bandwidth_capable() static

pcie_bandwidth_capable() is only used within pci.c, make it static.

Link: https://lore.kernel.org/r/20240507121758.13849-1-ilpo.jarvinen@linux.intel.com


Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>