src/soc/intel: Remove unused <stdlib.h>

Change-Id: I71a5a6c3748d5a3910970bfb1ec3d7ecd3184cfd
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33686
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/broadwell/minihd.c

@@ -21,7 +21,6 @@
 #include <device/pci_ids.h>
 #include <device/pci_ops.h>
 #include <device/mmio.h>
-#include <stdlib.h>
 #include <soc/intel/common/hda_verb.h>
 #include <soc/ramstage.h>
 #include <soc/igd.h>