ASoC: tegra20-spdif: remove "default m"

Make tegra20-spdif default to N as all other drivers do.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Fixes: 774fec33 ("ASoC: Tegra: Implement SPDIF CPU DAI")
Link: https://lore.kernel.org/r/8756eb5aac561173aa222c9cb64dd314ab1b1f9b.1603925200.git.mirq-linux@rere.qmqm.plSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/tegra/Kconfig

@@ -39,7 +39,6 @@ config SND_SOC_TEGRA20_I2S
 config SND_SOC_TEGRA20_SPDIF
 	tristate "Tegra20 SPDIF interface"
 	depends on SND_SOC_TEGRA
-	default m
 	help
 	  Say Y or M if you want to add support for the Tegra20 SPDIF interface.
 	  You will also need to select the individual machine drivers to support