rockchip: Port IO-domain driver for RK3568 from linux

rockchip: Port IO-domain driver for RK3568 from linux

Port the Rockchip IO-domain driver for RK3568 from linux.

The driver auto probe after bind to configure IO-domain based on the
regulator voltage. Compared to the linux driver this driver is not
notified about regulator voltage changes and only configure IO-domain
based on the initial voltage autoset by the regulator.

It is not recommended to enable MMC_IO_VOLTAGE or the mmc signal voltage
and IO-domain may end up out of sync.

Based on the linux commit 28b05a64e47c ("soc: rockchip: io-domain: add
rk3568 support").

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>