arm64: dts: Add support for Spreadtrum SC9836 SoC in dts and Makefile

Adds the device tree support for Spreadtrum SC9836 SoC which is based on
Sharkl64 platform.

Sharkl64 platform contains the common nodes of Spreadtrum's arm64-based SoCs.

Signed-off-by: Zhizhou Zhang <zhizhou.zhang@spreadtrum.com>
Signed-off-by: Orson Zhai <orson.zhai@spreadtrum.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>