reset: meson: add dt-bindings for meson-axg audio arb

Add dt-bindings for the audio memory arbiter found on Amlogic's
A113 based SoCs

Reviewed-by: Rob Herring <[e-mail]>
Signed-off-by: Jerome Brunet <[e-mail]>
Signed-off-by: Philipp Zabel <[e-mail]>

Documentation/devicetree/bindings/reset/amlogic,meson-axg-audio-arb.txt

···
+* Amlogic audio memory arbiter controller
+
+The Amlogic Audio ARB is a simple device which enables or
+disables the access of Audio FIFOs to DDR on AXG based SoC.
+
+Required properties:
+- compatible: 'amlogic,meson-axg-audio-arb'
+- reg: physical base address of the controller and length of memory
+       mapped region.
+- clocks: phandle to the fifo peripheral clock provided by the audio
+	  clock controller.
+- #reset-cells: must be 1.
+
+Example on the A113 SoC:
+
+arb: reset-controller@280 {
+	compatible = "amlogic,meson-axg-audio-arb";
+	reg = <0x0 0x280 0x0 0x4>;
+	#reset-cells = <1>;
+	clocks = <&clkc_audio AUD_CLKID_DDR_ARB>;
+};

include/dt-bindings/reset/amlogic,meson-axg-audio-arb.h

···
+/* SPDX-License-Identifier: (GPL-2.0 OR MIT)
+ *
+ * Copyright (c) 2018 Baylibre SAS.
+ * Author: Jerome Brunet <[e-mail]>
+ */
+
+#ifndef _DT_BINDINGS_AMLOGIC_MESON_AXG_AUDIO_ARB_H
+#define _DT_BINDINGS_AMLOGIC_MESON_AXG_AUDIO_ARB_H
+
+#define AXG_ARB_TODDR_A	0
+#define AXG_ARB_TODDR_B	1
+#define AXG_ARB_TODDR_C	2
+#define AXG_ARB_FRDDR_A	3
+#define AXG_ARB_FRDDR_B	4
+#define AXG_ARB_FRDDR_C	5
+
+#endif /* _DT_BINDINGS_AMLOGIC_MESON_AXG_AUDIO_ARB_H */