arm64: Add support for Spreadtrum's Sharkl64 Platform in Kconfig and defconfig

Adds support for Spreadtrum's SoC Platform in the arm64 Kconfig and
defconfig files.

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>