MAINTAINERS: Add public mailing list for ARC

commit 9acdc911 upstream.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

MAINTAINERS

@@ -8752,6 +8752,7 @@ F:	include/linux/swiotlb.h
 
 SYNOPSYS ARC ARCHITECTURE
 M:	Vineet Gupta <vgupta@synopsys.com>
+L:	linux-snps-arc@lists.infraded.org
 S:	Supported
 F:	arch/arc/
 F:	Documentation/devicetree/bindings/arc/