MAINTAINERS: Add entry for Bitmain SoC platform

Add MAINTAINERS entry for Bitmain SoC platform with myself as the
Maintainer.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>

MAINTAINERS

@@ -1372,6 +1372,13 @@ F:	arch/arm/mach-aspeed/
 F:	arch/arm/boot/dts/aspeed-*
 N:	aspeed
 
+ARM/BITMAIN ARCHITECTURE
+M:	Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
+S:	Maintained
+F:	arch/arm64/boot/dts/bitmain/
+F:	Documentation/devicetree/bindings/arm/bitmain.yaml
+
 ARM/CALXEDA HIGHBANK ARCHITECTURE
 M:	Rob Herring <robh@kernel.org>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)