uboot-phytec

rockchip: rk3288: move setup_led() to firefly-rk3288

Only firefly-rk3288 has the dts node "u-boot,boot-led",
while CONFIG_SPL_LED is not enable, move code to firefly-rk3288
now in case someone need this code.

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