KVM: arm64: Mark the kvmarm ML as moderated for non-subscribers

The kvmarm mailing list is moderated for non-subscriber, but that
was never advertised. Fix this with the hope that people will
eventually subscribe before posting, saving me the hassle of
letting their post through eventually.
Signed-off-by: Marc Zyngier <maz@kernel.org>

MAINTAINERS

@@ -9768,7 +9768,7 @@ R:	James Morse <james.morse@arm.com>
 R:	Alexandru Elisei <alexandru.elisei@arm.com>
 R:	Suzuki K Poulose <suzuki.poulose@arm.com>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
-L:	kvmarm@lists.cs.columbia.edu
+L:	kvmarm@lists.cs.columbia.edu (moderated for non-subscribers)
 S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm.git
 F:	arch/arm64/include/asm/kvm*