MAINTAINERS: Remove Mathieu Poirier as coresight maintainer

Mathieu Poirier is no longer involved in maintainig the CoreSight self-hosted
tracing subsystem.

Mathieu, Thank you very much creating and maintaing the subsystem all these
years !

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20230404111117.569795-1-suzuki.poulose@arm.com

CREDITS

@@ -3459,6 +3459,11 @@ D: several improvements to system programs
 S: Oldenburg
 S: Germany
 
+N: Mathieu Poirier
+E: mathieu.poirier@linaro.org
+D: CoreSight kernel subsystem, Maintainer 2014-2022
+D: Perf tool support for CoreSight
+
 N: Robert Schwebel
 E: robert@schwebel.de
 W: https://www.schwebel.de

MAINTAINERS

@@ -2091,7 +2091,6 @@ F:	arch/arm/boot/dts/cx92755*
 N:	digicolor
 
 ARM/CORESIGHT FRAMEWORK AND DRIVERS
-M:	Mathieu Poirier <mathieu.poirier@linaro.org>
 M:	Suzuki K Poulose <suzuki.poulose@arm.com>
 R:	Mike Leach <mike.leach@linaro.org>
 R:	Leo Yan <leo.yan@linaro.org>