arm: tegra: initial support for apalis tk1

arm: tegra: initial support for apalis tk1

This patch adds board support for the Toradex Apalis TK1 a computer on
module which can be used on different carrier boards.

The module consists of a Tegra TK1 SoC, a PMIC solution, 2 GB of DDR3L
RAM, a bunch of level shifters, an eMMC, a TMP451 temperature sensor
chip, an I210 gigabit Ethernet controller and a SGTL5000 audio codec.
Furthermore, there is a Kinetis MK20DN512 companion micro controller for
analogue, CAN and resistive touch functionality.

For the sake of ease of use we do not distinguish between different
carrier boards for now as the base module features are deemed
sufficient enough for regular booting.

The following functionality is working so far:
- eMMC boot, environment storage and Toradex factory config block
- Gigabit Ethernet
- MMC/SD cards (both MMC1 as well as SD1 slot)
- USB client/host (dual role OTG port as client e.g. for DFU/UMS or host,
  other two ports as host)

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Marcel Ziswiler <marcel@ziswiler.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>