soc/intel/apollolake: Include gpe.h in chip.h

This is required for using GPE_* macros in devicetree.cb.

BUG=chrome-os-partner:55670

Change-Id: I8f6f536df96cf8145bb0c03ec413fb2f374301b5
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/15946
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-by: Shaunak Saha <shaunak.saha@intel.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

src/soc/intel/apollolake/chip.h

@@ -18,6 +18,7 @@
 #ifndef _SOC_APOLLOLAKE_CHIP_H_
 #define _SOC_APOLLOLAKE_CHIP_H_
 
+#include <soc/gpe.h>
 #include <soc/gpio_defs.h>
 #include <soc/gpio.h>
 #include <soc/intel/common/lpss_i2c.h>