sb/intel/lynxpoint: Include <stdint.h> to fix compilation errors

If the file `southbridge/intel/lynxpoint/nvs.h` is included in a file
that does not already include <stdint.h>, compilation errors result.

Adding the necessary <stdint.h> inclusions fixes compilation for an
ASRock H81M-HDS.

Change-Id: Id0d14705282cc959146e00dd47754ee8a2e8e825
Signed-off-by: Tristan Corrick <tristan@corrick.kiwi>
Reviewed-on: https://review.coreboot.org/29389
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

src/southbridge/intel/lynxpoint/nvs.h

@@ -15,6 +15,7 @@
  */
 
 #include <commonlib/helpers.h>
+#include <stdint.h>
 #include "vendorcode/google/chromeos/gnvs.h"
 
 typedef struct global_nvs_t {

src/vendorcode/google/chromeos/gnvs.h

@@ -16,6 +16,8 @@
 #ifndef __VENDORCODE_GOOGLE_CHROMEOS_GNVS_H
 #define __VENDORCODE_GOOGLE_CHROMEOS_GNVS_H
 
+#include <stdint.h>
+
 #define BOOT_REASON_OTHER	0
 #define BOOT_REASON_S3DIAG	9