PCI: Extract ATS disabling to a helper function

Introduce quirk_no_ats() helper function to provide a standard way to
disable ATS capability in PCI quirks.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230908143606.685930-2-bartosz.pawlowski@intel.com
Signed-off-by: Bartosz Pawlowski <bartosz.pawlowski@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>