ASoC: atmel-ssc: distinguish whether SSC supports fslen ext

Add compatible string to distinguish whether SSC supports
frame sync length extension.

Signed-off-by: Bo Shen <voice.shen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2 files changed