bmp_logo: support CONFIG_DM_VIDEO

in case of bmp_logo, the video_bmp driver is used for
drawing a bmp logo. This driver supports only "full"
bmp data. Adding a logo with the bmp_logo tool to
u-boot binary adds currently only real data and drops
the bmp header.

This patch adds now the full bmp data to the u-boot
binary, so video_bmp driver works with the logo embedded
into u-boot.

Fixed also some checkpatch error poping up with this
patch.

Signed-off-by: Heiko Schocher <hs@denx.de>