uboot-phytec

ram: rockchip: update lpddr4 timing for rk3399

Update lpddr timing in lpddr4-400 and lpddr4-800 file from rockchip
vendor code;

Signed-off-by: YouMin Chen <cym@rock-chips.com>
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>