skylake: ACPI: Clean up pch.asl

Clean up the code in pch.asl:
- move all the C header includes into here instead of duplicated
in various ASL files included from here
- move the trap field definition into platform.asl with the method
- alphebetize the includes
- move gpio.asl include into pch.asl
- remove duplicate irqlinks.asl include from lpc.asl

BUG=chrome-os-partner:44622
BRANCH=none
TEST=emerge-glados coreboot

Change-Id: I51b1c5286fc344df6942a24c1dea71abf10ab561
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 3ee9c4afa031191d275f0d3d40b2b15b85369b2f
Original-Change-Id: I3bae434ad227273885d8436db23e17e593739f77
Original-Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/295903
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/11530
Tested-by: build bot (Jenkins)
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/soc/intel/skylake/acpi/gpio.asl

@@ -18,10 +18,6 @@
  * Foundation, Inc.
  */
 
-#include <soc/irq.h>
-#include <soc/iomap.h>
-#include <soc/pcr.h>
-#include <soc/gpio_defs.h>
 
 /* PCR Register Access Methods PCR Dword Read arg0: PID arg1: Offset */
 Method (PCRR, 2, Serialized)