arm: dts: Add devicetree for Hikey960 board

This commit adds devicetree for Hikey960 board. Most of the contents are
copied from Linux kernel with some modifications for u-boot. To be
more precise, SD card's speed related properties are removed due to a
bug in u-boot clock implementation. Hence forcing the SD controller to
work in standard speed.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index 9e7d6d6..ce1eacb 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -15,6 +15,7 @@
 	exynos4412-odroid.dtb
 
 dtb-$(CONFIG_TARGET_HIKEY) += hi6220-hikey.dtb
+dtb-$(CONFIG_TARGET_HIKEY960) += hi3660-hikey960.dtb
 
 dtb-$(CONFIG_TARGET_POPLAR) += hi3798cv200-poplar.dtb