rockchip: evb_rk3288: Add console settings

Add console settings like stdin, stdout and stderr as
usbkbd and vidconsole respectively for evb-rk3288 targets.

This would certainly help to detect the attached video
devices (like HDMI) and print the console messages on display.

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