drivers: misc: coresight: nrf_etr: Add support for turbo logs

Add support for optimized short log messages (aka turbo logs). They are
supported on cpuapp and co-processors owned by cpuapp (FLPR and PPR).
In general, it can be supported if cpuapp has access to logging strings
used for the log message. Currently mode is supported only in standalone
logging. When it is extended for dictionary logging then it will also
be supported on other cores (e.g. cpurad).

Signed-off-by: Krzysztof Chruściński <krzysztof.chruscinski@nordicsemi.no>