The log_backend_swo used system clock frequency
as a base for SWO clock calculation. This commit
corrects that by obtaining the needed value from DTS.
Signed-off-by: Piotr Zięcik <piotr.ziecik@nordicsemi.no>
This commit adds Serial Wire Output (SWO) logger backend. SWO is an
extension of Serial Wire Debug (SWD) port developed by ARM.
Signed-off-by: Piotr Mienkowski <piotr.mienkowski@gmail.com>