device: Add support for multiple PCI segment groups

Add initial support for multiple PCI segment groups. Instead of
modifying secondary in the bus struct introduce a new segment_group
struct element and keep existing common code.

Since all platforms currently only use 1 segment this is not a
functional change. On platforms that support more than 1 segment the
segment has to be set when creating the PCI domain.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: Ied3313c41896362dd989ee2ab1b1bcdced840aa8
Reviewed-on: https://review.coreboot.org/c/coreboot/+/79927
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Martin Roth <martin.roth@amd.corp-partner.google.com>
diff --git a/src/device/device_const.c b/src/device/device_const.c
index a63a629..c91c009 100644
--- a/src/device/device_const.c
+++ b/src/device/device_const.c
@@ -35,6 +35,7 @@
 	for (dev = all_devices; dev; dev = dev->next) {
 		if ((dev->path.type == DEVICE_PATH_PCI) &&
 		    (dev->bus->secondary == bus) &&
+		    (dev->bus->segment_group == 0) &&
 		    (dev->path.pci.devfn == devfn)) {
 			result = dev;
 			break;
@@ -233,7 +234,7 @@
 			dev = dev->next;
 			continue;
 		}
-		if (dev->bus->secondary == bus)
+		if (dev->bus->secondary == bus && dev->bus->segment_group == 0)
 			return pcidev_path_behind(dev->bus, devfn);
 		dev = dev->next;
 	}