atmel: common: Add function to display via DM_VIDEO's API

Add a function to display the company's logo and board information
via the API from DM_VIDEO. This function can be shared by other
atmel boards, so locate it in board/atmel/common folder.

Signed-off-by: Wenyou Yang <wenyou.yang@microchip.com>
Reviewed-by: Simon Glass <sjg@chromium.org>