ufs: Add MediaTek UFS driver

ufs: Add MediaTek UFS driver

Add the UFS driver for MediaTek platforms.

Loosely based on the Linux driver, this UFS driver can successfully get a
link and R/W access to the UFS chip on the MediaTek MT6878 mobile SoC,
when U-Boot is running as lk, or as the kernel (Secure world access is
not tested)

Signed-off-by: Igor Belwon <igor.belwon@mentallysanemainliners.org>
Link: https://patch.msgid.link/20251011-mtk-ufs-uboot-v1-3-a05f991ee150@mentallysanemainliners.org
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>