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/mainboard/google/link/acpi/ec.asl

@@ -20,5 +20,8 @@
 /* mainboard configuration */
 #include "../ec.h"
 
+/* Enable EC backed Keyboard Backlight in ACPI */
+#define EC_ENABLE_KEYBOARD_BACKLIGHT
+
 /* ACPI code for EC functions */
-#include "../../../../ec/google/chromeec/acpi/ec.asl"
+#include <ec/google/chromeec/acpi/ec.asl>

src/mainboard/google/link/acpi/mainboard.asl

@@ -85,23 +85,4 @@ Scope (\_SB) {
 			VendorShort (ADDR) {0x4a}
 		})
 	}
-
-	// Keyboard Backlight interface via EC
-	Device (KBLT) {
-		Name (_HID, EisaId("GGL0002"))
-		Name (_UID, 1)
-		Name (_ADR, 0)
-
-		// Read current backlight value
-		Method (KBQC, 0)
-		{
-			Return (\_SB.PCI0.LPCB.EC0.KBLV)
-		}
-
-		// Write new backlight value
-		Method (KBCM, 1)
-		{
-			Store (Arg0, \_SB.PCI0.LPCB.EC0.KBLV)
-		}
-	}
 }