coresight-etm4x: Support context-ID tracing when PID namespace is enabled

Like ETTv3, ETMv4 also needs the similar modifications to support Context
ID tracing when PID namespace is enabled.

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>