haswell boards: support added chromeos function

The get_write_protect_state() function was added to the
chromeos API that needs to be supported by the boards.
Implement this support.

Built and booted. Noted firmware select worked on an image with
RW firmware support. Also checked that recovery mode worked as
well by choosing the RO path.

Change-Id: Ifd213be25304163fc61d153feac4f5a875a40902
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/2855
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
diff --git a/src/mainboard/intel/wtm2/chromeos.c b/src/mainboard/intel/wtm2/chromeos.c
index 8142e65..7cc0ef4 100644
--- a/src/mainboard/intel/wtm2/chromeos.c
+++ b/src/mainboard/intel/wtm2/chromeos.c
@@ -71,3 +71,9 @@
 {
 	return 0; // force off
 }
+
+int get_write_protect_state(void)
+{
+	return 0;
+}
+