Merge branch 'pci/bwctrl'

- Add set_pcie_speed.sh to TEST_PROGS to fix issue when executing the
  set_pcie_cooling_state.sh test case (Yi Lai)

- Fix the pcie_bwctrl_select_speed() return value in cases where a
  non-compliant device doesn't advertise valid supported speeds (Ilpo
  Järvinen)

- Avoid a NULL pointer dereference when we run out of bus numbers to assign
  for a bridge secondary bus (Lukas Wunner)

* pci/bwctrl:
  PCI/bwctrl: Fix NULL pointer dereference on bus number exhaustion
  PCI/bwctrl: Fix pcie_bwctrl_select_speed() return type
  selftests/pcie_bwctrl: Add 'set_pcie_speed.sh' to TEST_PROGS