Add ddr driver for rk3588 to get the ram capacity. Co-developed-by: Jonas Karlman <jonas@kwiboo.se> Signed-off-by: Jonas Karlman <jonas@kwiboo.se> Signed-off-by: Jagan Teki <jagan@edgeble.ai> Reviewed-by: Kever Yang <kever.yang@rock-chips.com>