leds: netxbig: add device tree binding

This patch adds device tree support for the netxbig LEDs.

This also introduces a additionnal DT binding for the GPIO extension bus
(netxbig-gpio-ext) used to configure the LEDs. Since this bus could also
be used to control other devices, then it seems more suitable to have it
in a separate DT binding.

Signed-off-by: Simon Guinot <simon.guinot@sequanux.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

include/dt-bindings/leds/leds-netxbig.h

@@ -0,0 +1,18 @@
+/*
+ * This header provides constants for netxbig LED bindings.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef _DT_BINDINGS_LEDS_NETXBIG_H
+#define _DT_BINDINGS_LEDS_NETXBIG_H
+
+#define NETXBIG_LED_OFF		0
+#define NETXBIG_LED_ON		1
+#define NETXBIG_LED_SATA	2
+#define NETXBIG_LED_TIMER1	3
+#define NETXBIG_LED_TIMER2	4
+
+#endif /* _DT_BINDINGS_LEDS_NETXBIG_H */