dt-bindings: Add mfd/cros_ec definitions

Add a dt-bindings include file for cros_ec devicetree definition, define
a pair of special purpose PWM channels in it.

Signed-off-by: Fabio Baltieri <fabiobaltieri@chromium.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Author: fabiobaltieri

include/dt-bindings/mfd/cros_ec.h

@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+/*
+ * DTS binding definitions used for the Chromium OS Embedded Controller.
+ *
+ * Copyright (c) 2022 The Chromium OS Authors. All rights reserved.
+ */
+
+#ifndef _DT_BINDINGS_MFD_CROS_EC_H
+#define _DT_BINDINGS_MFD_CROS_EC_H
+
+/* Typed channel for keyboard backlight. */
+#define CROS_EC_PWM_DT_KB_LIGHT		0
+/* Typed channel for display backlight. */
+#define CROS_EC_PWM_DT_DISPLAY_LIGHT	1
+/* Number of typed channels. */
+#define CROS_EC_PWM_DT_COUNT		2
+
+#endif