MAINTAINERS: coresight: Add James Clark as Reviewer

James has made significant contributions to the CoreSight subsystem
both with code and reviews. Add James to the Reviewer for the subsystem.

Cc: James Clark <james.clark@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: James Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20230608152045.112349-1-suzuki.poulose@arm.com