ram: rk3399: Configure SLEWP_EN, SLEWN_EN for lpddr4

Configure SLEWP_EN, SLEWN_EN for lpddr4 during phy IO config.

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