chromeec: Move keyboard backlight code into Chrome EC directory

Since more boards are starting to use the EC provided keyboard
backlight interface move the code to a common place and allow
it to get included in mainboards.

Change-Id: I3f307bbce1a96cdd1c8224b1e89a63d6fedef738
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: http://review.coreboot.org/11478
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/ec/google/chromeec/acpi/ec.asl

@@ -420,6 +420,10 @@ Device (EC0)
 	#include "als.asl"
 #endif
 
+#ifdef EC_ENABLE_KEYBOARD_BACKLIGHT
+       #include "keyboard_backlight.asl"
+#endif
+
 #ifdef EC_ENABLE_PD_MCU_DEVICE
 	#include "pd.asl"
 #endif

src/ec/google/chromeec/acpi/keyboard_backlight.asl

@@ -0,0 +1,42 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2015 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc.
+ */
+
+Scope (\_SB)
+{
+	/*
+	 * Chrome EC Keyboard Backlight interface
+	 */
+	Device (KBLT)
+	{
+		Name (_HID, "GOOG0002")
+		Name (_UID, 1)
+
+		/* Read current backlight value */
+		Method (KBQC, 0, NotSerialized)
+		{
+			Return (\_SB.PCI0.LPCB.EC0.KBLV)
+		}
+
+		/* Write new backlight value */
+		Method (KBCM, 1, NotSerialized)
+		{
+			Store (Arg0, \_SB.PCI0.LPCB.EC0.KBLV)
+		}
+	}
+}