ARM: dts: imx6qdl-wandboard: Fix audio channel swap

When running a stress playback/stop loop test on a mx6wandboard channel
swaps can be noticed randomly.

Increasing the SGTL5000 LRCLK pad strength to its maximum value fixes
the issue, so add the 'lrclk-strength' property to avoid the audio
channel swaps.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx6qdl-wandboard.dtsi

@@ -88,6 +88,7 @@
 		clocks = <&clks IMX6QDL_CLK_CKO>;
 		VDDA-supply = <&reg_2p5v>;
 		VDDIO-supply = <&reg_3p3v>;
+		lrclk-strength = <3>;
 	};
 };