vc/cavium/bdk/libbdk-arch/bdk-numa.c: Fix old-style function definition

Change-Id: Ia56f813933143ef69c97f1b7643693c6eade6abe
Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/70256
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>

src/vendorcode/cavium/bdk/libbdk-arch/bdk-numa.c

@@ -89,7 +89,7 @@ int bdk_numa_exists(bdk_node_t node)
  *
  * @return
  */
-extern int bdk_numa_is_only_one()
+extern int bdk_numa_is_only_one(void)
 {
 	/* FIXME(dhendrix): stub */
 	return 1;