GCC4.6: Squash warning in cfb_console.c

cfb_console.c: In function 'video_display_bitmap':
cfb_console.c:1148: warning: format '%d' expects type 'int', but argument 2 has
type 'long unsigned int'
cfb_console.c:1148: warning: format '%d' expects type 'int', but argument 3 has
type 'long unsigned int'

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Mike Frysinger <vapier@gentoo.org>