dts: bindings: arm: nordic: Add TDDCONF sources

For nrf54h20 a range of combinations exist to configure the test and
debug domains data sources and sinks. Expose them in DTS to allow
configuring them. Also drop the previous style which was too rigid to
extend to cover all cases cleanly. The old style was only used in a
single sample application so far.

Signed-off-by: Karsten Koenig <karsten.koenig@nordicsemi.no>