Enable pin control support for SWO log backend, by creating a new
ITM node for the ARM instrumentation trace macrocell. Add pin control
properties under this node, and refactor the swo-req-freq property to be
defined within this node.
Signed-off-by: Daniel DeGrasse <daniel.degrasse@nxp.com>
Added file with common properties for cortex-m cores.
Added optional swo-ref-frequency property.
Signed-off-by: Krzysztof Chruscinski <krzysztof.chruscinski@nordicsemi.no>