MAINTAINERS: Add James and Mike as Arm64 performance events reviewers

MAINTAINERS: Add James and Mike as Arm64 performance events reviewers

James, Mike and Leo have been doing all the reviews and development work
for the Coresight perf tools for a couple of years now.  As such remove
my name and add James and Mike as official reviewers (Leo is already
listed as such).

Signed-off-by: Mathieu Poirier <[email protected]>
Cc: James Clark <[email protected]>
Cc: Leo Yan <[email protected]>
Cc: Mike Leach <[email protected]>
Cc: [email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>