ASoC: tegra: add tegra sgtl5000 machine driver

This binding and driver describe/support playback to headphones, and
capture from line-in and microphone.

This driver is useful for the Toradex Apalis T30, Apalis TK1 and
Colibri T30 modules.

Signed-off-by: Marcel Ziswiler <marcel@ziswiler.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>