spi: mediatek: Add spi bus for Mediatek MT8173

This patch adds basic spi bus for MT8173.

Signed-off-by: Leilk Liu <leilk.liu@mediatek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --cc drivers/spi/Kconfig
Simple merge

diff --cc drivers/spi/Makefile
Simple merge

diff --cc drivers/spi/spi-mt65xx.c
Simple merge

diff --cc include/linux/platform_data/spi-mt65xx.h
Simple merge