src/device: Clean up includes

Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Change-Id: Idd78271f2158bdc29ce9ac8d81f46ad8cbe84c5e
Reviewed-on: https://review.coreboot.org/c/coreboot/+/68205
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martin.roth@amd.corp-partner.google.com>

src/device/resource_allocator_common.c

@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
 #include <device/device.h>
+#include <stddef.h>
 
 struct pick_largest_state {
 	struct resource *last;