ARM: dts: r8a7743: Add audio clocks

Describe the external audio clocks required by the sound driver.
Boards that provide audio clocks need to override the clock frequencies.
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Reviewed-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7743.dtsi

@@ -1238,6 +1238,29 @@ extal_clk: extal {
 		clock-frequency = <0>;
 	};
 
+	/*
+	 * The external audio clocks are configured as 0 Hz fixed frequency
+	 * clocks by default.
+	 * Boards that provide audio clocks should override them.
+	 */
+	audio_clk_a: audio_clk_a {
+		compatible = "fixed-clock";
+		#clock-cells = <0>;
+		clock-frequency = <0>;
+	};
+
+	audio_clk_b: audio_clk_b {
+		compatible = "fixed-clock";
+		#clock-cells = <0>;
+		clock-frequency = <0>;
+	};
+
+	audio_clk_c: audio_clk_c {
+		compatible = "fixed-clock";
+		#clock-cells = <0>;
+		clock-frequency = <0>;
+	};
+
 	/* External USB clock - can be overridden by the board */
 	usb_extal_clk: usb_extal {
 		compatible = "fixed-clock";