level .gitignore that ignores everything is asking for future troubles..

This should have been part of b8b572e (powerpc: Move include files to
arch/powerpc/include/asm, 2008-08-01).

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kç2;ë