sb/intel/lynxpoint/lp_gpio.h: Include stdint.h

The struct definition makes use of types defined in that header.

Change-Id: I1d989298b8bf6266905330491c136874be7f5e28
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41475
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

src/southbridge/intel/lynxpoint/lp_gpio.h

@@ -3,6 +3,8 @@
 #ifndef INTEL_LYNXPOINT_LP_GPIO_H
 #define INTEL_LYNXPOINT_LP_GPIO_H
 
+#include <stdint.h>
+
 /* LynxPoint LP GPIOBASE Registers */
 #define GPIO_OWNER(set)		(0x00 + ((set) * 4))
 #define GPIO_PIRQ_APIC_EN	0x10