tegra: dts: Sync tegra20.dtsi with Linux v4.4

tegra: dts: Sync tegra20.dtsi with Linux v4.4

This file has changed quite a bit since it was set up. Sync it back with
Linux v4.4. Adjust the users slightly to cope with the changes:

- the host1x node is now called host1x@50000000
- we need a clocks node to provide the clk32k_in phandle
- active usb nodes need status = "okay"
- active i2c nodes need status = "okay"

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>