ARM: tegra: add Jetson TK1 device tree

Jetson TK1 is an NVIDIA Tegra124 development board, containing Tegra124,
2GB RAM, eMMC, SD card, SPI flash, serial port, PCIe Ethernet, HDMI,
audio, mini PCIe, JTAG, SATA, and an expansion IO connector containing
GPIOs, I2C, SPI, CSI, eDP, etc.

The following features work with this device tree: UART, SD card, eMMC,
SPI flash, USB (full-size jack, and mini-PCIe), audio, AS3722 RTC, system
power-off, suspend/resume (LP1) with wake via RTC alarm.

The following features should work with this device tree, but are not
validated: Expansion I2C, expansion SPI, expansion GPIO, gpio-key for the
power button.

The following features are not yet implemented in this device tree: Most
voltage regulators, expansion UART, HDMI, eDP, PCIe (Ethernet, and mini-
PCIe connector), CSI, SATA.

Signed-off-by: Stephen Warren <swarren@nvidia.com>