ram: rk3399: Update lpddr4 mode_sel based on io settings

The mode_sel on lpddr4 value is depending on IO settings
of rd_vref.

Add support for it.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Signed-off-by: YouMin Chen <cym@rock-chips.com>
1 file changed