arm64: dts: bitmain: Add BM1880 SoC support

Add devicetree support for Bitmain BM1880 SoC, consisting of a Dual
core ARM Cortex A53 subsystem, a Single core RISC-V subsystem and a Tensor
Processor subsystem. Only ARM Cortex A53 Application processor subsystem
support is enabled for now.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>