ASoC: fsl_esai: Add new compatible string for imx8qm

Add new compatible string "fsl,imx8qm-esai" in the binding document.
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/fade597f6fb7e0ef9eb1185b491eaa46a9d287e3.1589537601.git.shengjiu.wang@nxp.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/fsl,esai.txt

@@ -12,6 +12,7 @@ Required properties:
 			  "fsl,imx35-esai",
 			  "fsl,vf610-esai",
 			  "fsl,imx6ull-esai",
+			  "fsl,imx8qm-esai",
 
   - reg			: Offset and length of the register set for the device.