efifb/imacfb consolidation + hardware support

Remove imacfb entirely, merging its DMI table into the (otherwise very
similar) efifb driver.  This also adds hardware support for many of the
newer Intel Apple hardware.  This has been fairly well tested; we've been
shipping it in Fedora for some time.

Signed-off-by: Peter Jones <pjones@redhat.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: Jaya Kumar <jayakumar.lkml@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>