Coresight platform support assumes that a missing "cpu" phandle
defaults to CPU0. This could be problematic and unnecessarily binds
components to CPU0, where they may not be. Let us make the DT binding
rules a bit stricter by not defaulting to CPU0 for missing "cpu"
affinity information.
Also in coresight etm and cpu-debug drivers, abort the probe
for such cases.
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@xxxxxxxxxxxxxx>