arm: actions: add S700 SoC device tree

This patch adds .dtsi file(sync with Linux 5.5-rc6 with hash "b3a987b0264d")
and required binding for S700 SoC that is a 64-bit Quad-core ARM
Cortex-A53 cores.

It also provisions dts file to be built based on selected
platform(CONFIG_MACH_S900/S700).

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com>
diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index ba96efa..af7d804 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -66,6 +66,8 @@
 
 dtb-$(CONFIG_MACH_S900) += \
 	bubblegum_96.dtb
+dtb-$(CONFIG_MACH_S700) += \
+	s700-cubieboard7.dtb
 
 dtb-$(CONFIG_ROCKCHIP_PX30) += \
 	px30-evb.dtb \