MAINTAINERS: Mark the OP-TEE mailing list moderated

After sending a patch to op-tee@lists.trustedfirmware.org, I got the
typical response for a moderated list:

    Your mail to 'op-tee@lists.trustedfirmware.org' with the subject

	[...]

    Is being held until the list moderator can review it for approval.

    The message is being held because:

	The message is not from a list member

    Either the message will get posted to the list, or you will receive
    notification of the moderator's decision.

Mark this mailing list moderated in MAINTAINERS.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

Author: geertu

MAINTAINERS

@@ -19511,14 +19511,14 @@ F:	drivers/net/phy/ncn*
 
 OP-TEE DRIVER
 M:	Jens Wiklander <jens.wiklander@linaro.org>
-L:	op-tee@lists.trustedfirmware.org
+L:	op-tee@lists.trustedfirmware.org (moderated for non-subscribers)
 S:	Maintained
 F:	Documentation/ABI/testing/sysfs-bus-optee-devices
 F:	drivers/tee/optee/
 
 OP-TEE RANDOM NUMBER GENERATOR (RNG) DRIVER
 M:	Sumit Garg <sumit.garg@kernel.org>
-L:	op-tee@lists.trustedfirmware.org
+L:	op-tee@lists.trustedfirmware.org (moderated for non-subscribers)
 S:	Maintained
 F:	drivers/char/hw_random/optee-rng.c
 
@@ -25617,7 +25617,7 @@ F:	include/media/i2c/tw9910.h
 TEE SUBSYSTEM
 M:	Jens Wiklander <jens.wiklander@linaro.org>
 R:	Sumit Garg <sumit.garg@kernel.org>
-L:	op-tee@lists.trustedfirmware.org
+L:	op-tee@lists.trustedfirmware.org (moderated for non-subscribers)
 S:	Maintained
 F:	Documentation/ABI/testing/sysfs-class-tee
 F:	Documentation/driver-api/tee.rst