MAINTAINERS: fbdev is orphaned

Tony hasn't been heard from in 18 months and people keep sending him
things.

Cc: Joe Perches <joe@perches.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>