ASoC: spdif: Add stub DAPM widgets for Rx
ASoC: spdif: Add stub DAPM widgets for Rx

Ensure that the driver continues to work with mandatory DAPM.

Signed-off-by: Mark Brown <b51b9a92386687a9ac927cebfa0f978adeb8cea5@linaro.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs