coresight: adding support for beagle and beagleXM

Currently supporting ETM and ETB.  Support for TPIU
and SDTI are yet to be added.

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