Rockchip platform use TPL to do the DRAM initialize for all the SoCs, if TPL is not available, means no available DRAM init program, and the u-boot-rockchip.bin is not functionable. Signed-off-by: Kever Yang <kever.yang@rock-chips.com> Change-Id: I2299f1eddce5aa7d5fb1a3fb4d8aeaa995b397fa