dt-bindings: fsl-imx-sdma: fix HDMI audio index

dt-bindings: fsl-imx-sdma: fix HDMI audio index

HDMI Audio has been added to the DT binding documentation with an
incorrect index. DT and the driver use index 26. This happened,
because the binding is missing MULTI_SAI type, which is using
index 25.

Reported-by: Michael Yackavage <michaely@ips-yes.com>
Fixes: 7bdbd87d4008 ("dt-bindings: fsl-imx-sdma: Convert imx sdma to DT schema")
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Link: https://lore.kernel.org/r/20240226212740.2019837-6-sre@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>