ARM: dts: omap3: Add missing #sound-dai-cells

dtc now gives the following warnings:

arch/arm/boot/dts/omap3-gta04a3.dtb: Warning (sound_dai_property): /sound_telephony/simple-audio-card,cpu: Missing property '#sound-dai-cells' in node /ocp@68000000/mcbsp@49026000 or bad phandle (referred from sound-dai[0])
arch/arm/boot/dts/omap3-gta04a4.dtb: Warning (sound_dai_property): /sound_telephony/simple-audio-card,cpu: Missing property '#sound-dai-cells' in node /ocp@68000000/mcbsp@49026000 or bad phandle (referred from sound-dai[0])
arch/arm/boot/dts/omap3-gta04a5.dtb: Warning (sound_dai_property): /sound_telephony/simple-audio-card,cpu: Missing property '#sound-dai-cells' in node /ocp@68000000/mcbsp@49026000 or bad phandle (referred from sound-dai[0])

Add the missing #sound-dai-cells property.

Cc: "Benoît Cousson" <bcousson@baylibre.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: linux-omap@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/omap3.dtsi

@@ -557,6 +557,7 @@ mcbsp4: mcbsp@49026000 {
 			dma-names = "tx", "rx";
 			clocks = <&mcbsp4_fck>;
 			clock-names = "fck";
+			#sound-dai-cells = <0>;
 			status = "disabled";
 		};