PCI: Simplify pcie_capability_clear_and_set_word() to ..._clear_word()

When using pcie_capability_clear_and_set_word() but not actually *setting*
anything, use pcie_capability_clear_word() instead.

Link: https://lore.kernel.org/r/20231026121924.2164-1-ilpo.jarvinen@linux.intel.com
Link: https://lore.kernel.org/r/20231026121924.2164-2-ilpo.jarvinen@linux.intel.com


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