Update MAINTAINERS to add reviewer for CoreSight

Added myself as a designated reviewer for the CoreSight infrastructure
at the request of Mathieu Poirier.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200320165303.13681-13-mathieu.poirier@linaro.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>