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/icelake/pmutil.c

@@ -29,7 +29,6 @@
 #include <intelblocks/pmclib.h>
 #include <intelblocks/rtc.h>
 #include <intelblocks/tco.h>
-#include <stdlib.h>
 #include <soc/espi.h>
 #include <soc/gpe.h>
 #include <soc/gpio.h>