PCI: Use PCI_HEADER_TYPE_* instead of literals

PCI: Use PCI_HEADER_TYPE_* instead of literals

Replace literals under drivers/pci/ with PCI_HEADER_TYPE_MASK,
PCI_HEADER_TYPE_NORMAL, and PCI_HEADER_TYPE_MFD.

Also replace !! boolean conversions with FIELD_GET().

Link: https://lore.kernel.org/r/20231003125300.5541-4-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com> # for Renesas R-Car