arm: octeontx: Add support for OcteonTX SoC platforms

This patch adds support for all OcteonTX 81xx/83xx
boards from Marvell.
For 81xx boards, use octeontx_81xx_defconfig and
for 83xx boards, use octeontx_83xx_defconfig.

Signed-off-by: Suneel Garapati <sgarapati@marvell.com>
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index bf3890e..87b4198 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -80,6 +80,7 @@
 machine-$(CONFIG_ARCH_SUNXI)		+= sunxi
 machine-$(CONFIG_ARCH_TEGRA)		+= tegra
 machine-$(CONFIG_ARCH_U8500)		+= u8500
+machine-$(CONFIG_ARCH_OCTEONTX)		+= octeontx
 machine-$(CONFIG_ARCH_UNIPHIER)		+= uniphier
 machine-$(CONFIG_ARCH_VERSAL)		+= versal
 machine-$(CONFIG_ARCH_ZYNQ)		+= zynq