spi: atcspi200: Add support for Andes ATCSPI200 SPI

Merge series from CL Wang <cl634@andestech.com>:

This series adds support for the Andes ATCSPI200 SPI controller.

diff --cc MAINTAINERS
Simple merge

diff --cc drivers/spi/Kconfig
Simple merge

diff --cc drivers/spi/Makefile
Simple merge