MAINTAINERS: Add Jens as arm TEE reviewer

Add Jens as arm TEE reviewers so that he is informed of changes in FF-A
or OPTEE changes in Xen and can review them.

Signed-off-by: Bertrand Marquis <bertrand.marquis@arm.com>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>

MAINTAINERS

@@ -547,6 +547,7 @@ F:	stubdom/
 TEE MEDIATORS
 M:	Volodymyr Babchuk <volodymyr_babchuk@epam.com>
 M:	Bertrand Marquis <bertrand.marquis@arm.com>
+R:	Jens Wiklander <jens.wiklander@linaro.org>
 S:	Supported
 F:	xen/arch/arm/include/asm/tee/
 F:	xen/arch/arm/tee/