device/device.h: Rename busses for clarity

This renames bus to upstream and link_list to downstream.

Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Change-Id: I80a81b6b8606e450ff180add9439481ec28c2420
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78330
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
diff --git a/src/southbridge/amd/pi/hudson/lpc.c b/src/southbridge/amd/pi/hudson/lpc.c
index 266d75c..66ec824 100644
--- a/src/southbridge/amd/pi/hudson/lpc.c
+++ b/src/southbridge/amd/pi/hudson/lpc.c
@@ -171,8 +171,8 @@
 	reg_var[0] = pci_read_config16(dev, 0x64);
 
 	struct device *child;
-	if (dev->link_list) {
-		for (child = dev->link_list->children; child; child = child->sibling) {
+	if (dev->downstream) {
+		for (child = dev->downstream->children; child; child = child->sibling) {
 			if (child->enabled && (child->path.type == DEVICE_PATH_PNP)) {
 				struct resource *res;
 				for (res = child->resource_list; res; res = res->next) {