ARM: tegra: apalis-tk1: Fix high speed UART compatible

Turns out the compatible "nvidia,tegra124-hsuart" does not (yet) exist
and everybody else also uses it only in conjunction with
"nvidia,tegra30-hsuart".

Reported-by: Martin Šafařík <msafarik@retia.cz>
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>