src/southbridge: Use 'include <stdlib.h>' when appropriate

Also, including <types.h>, is supposed to provide stdint and stddef.

Change-Id: I7e1a3483aae0e3f0a7bc2eb2c1862ae7a325fd9c
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33683
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>
diff --git a/src/southbridge/amd/agesa/hudson/sm.c b/src/southbridge/amd/agesa/hudson/sm.c
index b5739f9..07646c8 100644
--- a/src/southbridge/amd/agesa/hudson/sm.c
+++ b/src/southbridge/amd/agesa/hudson/sm.c
@@ -19,7 +19,7 @@
 #include <device/smbus.h>
 #include <cpu/x86/lapic.h>
 #include <arch/ioapic.h>
-#include <stdlib.h>
+
 #include "hudson.h"
 #include "smbus.c"