MAINTAINERS: add Calxeda Highbank ARM platform

Adding maintainer for arch/arm/mach-highbank/
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Shawn Guo <shawn.guo@linaro.org>

MAINTAINERS

@@ -688,6 +688,12 @@ F:	drivers/mtd/nand/bcm_umi_nand.c
 F:	drivers/mtd/nand/bcm_umi_bch.c
 F:	drivers/mtd/nand/nand_bcm_umi.h
 
+ARM/CALXEDA HIGHBANK ARCHITECTURE
+M:	Rob Herring <rob.herring@calxeda.com>
+L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
+S:	Maintained
+F:	arch/arm/mach-highbank/
+
 ARM/CAVIUM NETWORKS CNS3XXX MACHINE SUPPORT
 M:	Anton Vorontsov <avorontsov@mvista.com>
 S:	Maintained