coresight: etb10: Add support for CLAIM tag

Following in the footstep of what was done for other CoreSight devices,
add CLAIM tag support to ETB10 in order to synchronise access to the
HW between the kernel and an external agent.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>