device: Add inline method to identify PATH_ROOT

Add and use inline method to identify the root device.

Change-Id: I394c8668245bcfea6414b8ca5f14ef8135897e59
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80169
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
diff --git a/src/include/device/device.h b/src/include/device/device.h
index cd0999a..863299c 100644
--- a/src/include/device/device.h
+++ b/src/include/device/device.h
@@ -458,6 +458,15 @@
  */
 #define config_of_soc()		__pci_0_00_0_config
 
+static inline bool is_root_device(const struct device *dev)
+{
+	if (!dev || !dev->bus)
+		return false;
+
+	return (dev->path.type == DEVICE_PATH_ROOT) ||
+	       (dev->bus->dev == dev);
+}
+
 void enable_static_device(struct device *dev);
 void enable_static_devices(struct device *bus);
 void scan_smbus(struct device *bus);