device/root_device: Consolidate common _scan_bus() functions

scan_usb_bus() and root_dev_scan_bus() had the very same implementation.
So rename the latter to scan_static_bus() and use that for both cases.

Change-Id: If0aba9c690b23e3716f2d47ff7a8c3e8f6d82679
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31901
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/include/device/device.h b/src/include/device/device.h
index 96fc837..a7ba5a9 100644
--- a/src/include/device/device.h
+++ b/src/include/device/device.h
@@ -331,7 +331,7 @@
 void scan_smbus(struct device *bus);
 void scan_generic_bus(struct device *bus);
 void scan_lpc_bus(struct device *bus);
-void scan_usb_bus(struct device *bus);
+void scan_static_bus(struct device *bus);
 
 #endif /* !defined(__ROMCC__) */