board: ge: bx50v3: Fix message output to video console

Use vidconsole for output to the LCD, now that DM_VIDEO is used.  Write
white text on a black background, like before migrating to DM_VIDEO.

Signed-off-by: Ian Ray <ian.ray@ge.com>
Signed-off-by: Robert Beckett <bob.beckett@collabora.com>