MAINTAINERS: add Bertrand to the ARM reviewers

Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Acked-by: Bertrand Marquis <bertrand.marquis@arm.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Release-Acked-by: Ian Jackson <iwj@xenproject.org>

MAINTAINERS

@@ -232,6 +232,7 @@ ARM (W/ VIRTUALISATION EXTENSIONS) ARCHITECTURE
 M:	Stefano Stabellini <sstabellini@kernel.org>
 M:	Julien Grall <julien@xen.org>
 R:	Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>
+R:	Bertrand Marquis <bertrand.marquis@arm.com>
 S:	Supported
 L:	xen-devel@lists.xenproject.org
 F:	docs/misc/arm/