kbuild: drivers/video/logo/ - fix ident glitch

Jan Engelhardt <jengelh@linux01.gwdg.de> wrote:
while compiling 2.6.17-rc2 with allyesconfig, this showed up:
...
  LOGO  drivers/video/logo/logo_superh_clut224.c
  CC      drivers/video/logo/logo_linux_mono.o
...

A tab had sneaked in. Convert it to a few spaces.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>