uboot-imx

video, cfb_console: make background and foreground color configurable

make CONSOLE_BG_COL/CONSOLE_FG_COL configurable through board config file.
Clear video screen in video_init().

Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Anatolij Gustschin <agust@denx.de>