pciexp_device: Propagate above-4G flag to all hotplug devices

The `IORESOURCE_ABOVE_4G` flag was only explicitly set for our dummy
device that reserves resources behind a hotplug port. The current re-
source allocator implicitly extends this to all devices below the port,
including real ones. Let's make that explicit, so future changes to the
allocator can't break this rule.

Change-Id: Id4c90b60682cf5c8949cde25362d286625b3e953
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/66719
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>

src/device/device_util.c

@@ -5,6 +5,7 @@
 #include <device/path.h>
 #include <device/pci_def.h>
 #include <device/resource.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -939,6 +940,15 @@ const char *dev_path_name(enum device_path_type type)
 	return type_name;
 }
 
+bool dev_path_hotplug(const struct device *dev)
+{
+	for (dev = dev->bus->dev; dev != dev->bus->dev; dev = dev->bus->dev) {
+		if (dev->hotplug_port)
+			return true;
+	}
+	return false;
+}
+
 void log_resource(const char *type, const struct device *dev, const struct resource *res,
 			const char *srcfile, const int line)
 {