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/drivers/usb/hub/acpi.c b/src/drivers/usb/hub/acpi.c
index e26d584..3944952 100644
--- a/src/drivers/usb/hub/acpi.c
+++ b/src/drivers/usb/hub/acpi.c
@@ -41,7 +41,7 @@
 	struct device *port = NULL;
 	unsigned int child_count = 0;
 
-	while ((port = dev_bus_each_child(dev->link_list, port)) != NULL) {
+	while ((port = dev_bus_each_child(dev->downstream, port)) != NULL) {
 		if (child_count++ >= config->port_count) {
 			printk(BIOS_WARNING, "%s cannot be added. Port Count limit reached.\n",
 			       dev_name(port));