src: Add missing include <stdint.h>

Change-Id: Idf10a09745756887a517da4c26db7a90a1bf9543
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/29403
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

src/superio/nuvoton/npcd378/npcd378.h

@@ -17,6 +17,8 @@
 #ifndef SUPERIO_NUVOTON_NPCD378_H
 #define SUPERIO_NUVOTON_NPCD378_H
 
+#include <stdint.h>
+
 /* HWM at LDN8 */
 #define NPCD837_HWM_WRITE_LOCK_CTRL 0x4
 #define NPCD837_HWM_WRITE_LOCK_BIT 0x1