rockchip: dts: rk3399: rock-pi-4: Use LPDDR4-100 dtsi

rockchip: dts: rk3399: rock-pi-4: Use LPDDR4-100 dtsi

Use LPDDR4-100 sdram timings dtsi for RockPI-4 board.

All these timings are processed during TPL stage of rock-pi-4 board,
bootchain. This make TPL would replace rockchip in house rkbin in
current bootchain.

Bootchain after and before this change:

   TPL -> SPL -> U-Boot proper

 rkbin -> SPL -> U-Boot proper

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Kever Yang <Kever.yang@rock-chips.com>