The ESAI of i.MX8QM is the same as i.MX6ULL. So add fsl,imx6ull-esai for
esai.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Fixes: adf7ea48 ("ASoC: dt-bindings: fsl-esai: allow fsl,imx8qm-esai fallback to fsl,imx6ull-esai")
Signed-off-by: Shawn Guo <shawnguo@kernel.org>