asm-generic/tlb.h: build fix

bring back the avr32, blackfin, sh, sparc architectures into working order,
by reverting the effects of this change that came in via the x86 tree:

   commit a5a19c63


   Author: Jeremy Fitzhardinge <jeremy@goop.org>
   Date:   Wed Jan 30 13:33:39 2008 +0100

       x86: demacro asm-x86/pgalloc_32.h

Sorry about that!

Signed-off-by: Ingo Molnar <mingo@elte.hu>