ARM: tegra: colibri_t30: annotate uarts and move compatible to board

Annotate UARTs and move the serial UART "nvidia,tegra30-hsuart"
compatible definitions from the carrier board to the module level device
trees. One could still override this in a custom carrier board device
tree if required.

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>