ASoC: Remove default settings from Tegra Kconfig

There needs to be a strong reason for overriding the Kconfig default.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>

sound/soc/tegra/Kconfig

@@ -1,14 +1,12 @@
 config SND_SOC_TEGRA
 	tristate "SoC Audio for the Tegra System-on-Chip"
 	depends on ARCH_TEGRA && TEGRA_SYSTEM_DMA
-	default m
 	help
 	  Say Y or M here if you want support for SoC audio on Tegra.
 
 config SND_SOC_TEGRA_I2S
 	tristate
 	depends on SND_SOC_TEGRA
-	default m
 	help
 	  Say Y or M if you want to add support for codecs attached to the
 	  Tegra I2S interface. You will also need to select the individual
@@ -25,7 +23,6 @@ config SND_SOC_TEGRA_WM8903
 	tristate "SoC Audio support for Tegra boards using a WM8903 codec"
 	depends on SND_SOC_TEGRA && I2C
 	depends on MACH_HAS_SND_SOC_TEGRA_WM8903
-	default m
 	select SND_SOC_TEGRA_I2S
 	select SND_SOC_WM8903
 	help