vendorcode/cavium/bdk/libbdk-hal/bdk-qlm.c: Add missing <stdlib.h>

Change-Id: I70029700bfb297ac06561056da730731a2ca1e8b
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33682
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/vendorcode/cavium/bdk/libbdk-hal/bdk-qlm.c

@@ -37,6 +37,7 @@
 * ARISING OUT OF USE OR PERFORMANCE OF THE SOFTWARE LIES WITH YOU.
 ***********************license end**************************************/
 #include <bdk.h>
+#include <stdlib.h>
 #include <string.h>
 #include "libbdk-arch/bdk-csrs-gser.h"
 #include "libbdk-arch/bdk-csrs-gsern.h"