There are two spdif IP on imx8mq, spdif1 is for normal
spdif device, spdif2 is for HDMI ARC interface.

Enable these spdif sound card in this patch.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>