ARC: Add self to MAINTAINERS

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

MAINTAINERS

@@ -7418,6 +7418,12 @@ F:	lib/swiotlb.c
 F:	arch/*/kernel/pci-swiotlb.c
 F:	include/linux/swiotlb.h
 
+SYNOPSYS ARC ARCHITECTURE
+M:	Vineet Gupta <vgupta@synopsys.com>
+L:	linux-snps-arc@vger.kernel.org
+S:	Supported
+F:	arch/arc/
+
 SYSV FILESYSTEM
 M:	Christoph Hellwig <hch@infradead.org>
 S:	Maintained