Move the BGRT image to use the same video_image linker-list approach
as the other embedded image. Move it into the drivers/video/images
directory and rename it to 'bgrt.bmp' since we know it is an image.
Drop the old bgrt Makefile rule as it is no-longer needed.
Co-developed-by: Claude <noreply@anthropic.com>
Signed-off-by: Simon Glass <sjg@chromium.org>