x86: page.h: move things back to their own files

# HG changeset patch
# User Jeremy Fitzhardinge <jeremy@xensource.com>
# Date 1199321648 28800
# Node ID 22f6a5902285b58bfc1fbbd9e183498c9017bd78
# Parent  bba9287641ff90e836d090d80b5c0a846aab7162
x86: page.h: move things back to their own files

Oops, asm/page.h has turned into an #ifdef hellhole.  Move
32/64-specific things back to their own headers to make it somewhat
comprehensible...

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>