device/device_util: Add and use is_pci_bridge()

TEST=Build and boot on intel/archercity CRB

Change-Id: Ied4921f7dc7e144e580d05d4f2262777aa59d895
Signed-off-by: Shuo Liu <shuo.liu@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/81566
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/device/device_util.c

@@ -930,3 +930,8 @@ bool is_pci_dev_on_bus(const struct device *pci, unsigned int bus)
 	return is_pci(pci) && pci->upstream->segment_group == 0
 		&& pci->upstream->secondary == bus;
 }
+
+bool is_pci_bridge(const struct device *pci)
+{
+	return is_pci(pci) && ((pci->hdr_type & 0x7f) == PCI_HEADER_TYPE_BRIDGE);
+}