This adds Kconfig options for the Tegra30 AHUB and I2S controller, and
updates the Tegra+WM8903 machine driver Kconfig to select those.

Includes a squashed bugfix from Sumit Bhattacharya <sumitb@nvidia.com>
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>