[A75][DTS] enable audio stereo play and set micbias resistor

In order to correctly play stereo audio, lrclk-strength must be set to
the maximum value of 0x3. Set micbias resistor to it's actual value (2k)
for better quality recording

arch/arm/boot/dts/seco/seco-imx6qdl-a75.dtsi

@@ -385,6 +385,8 @@
 		clocks       = <&clks IMX6QDL_CLK_CKO>;
 		VDDA-supply  = <&reg_2p5v_sgtl5000>;
 		VDDIO-supply = <&reg_3p3v_sgtl5000>;
+		micbias-resistor-k-ohms = <2>;
+		lrclk-strength = <0x3>;
 		status       = "okay";
 	};
 };