rockchip: roc-rk3399-pc: Add custom led_setup()

rockchip: roc-rk3399-pc: Add custom led_setup()

roc-rk3399-pc has some specific requirements to support LEDS,
environment. board detection and etc prior to U-Boot proper.

So as of now SPL would be a better stage for these custom board
requirements to support unlike TPL. Adding few of these custom
requirements like LEDS in TPL would require extra code pulling
and also the size of TPL can grow.

So, this patch moves the leds code from TPL into SPL Board init
led_setup code.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
(split tpl.c change as separate patch)
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>