x86, CPA: Change idmap attribute before ioremap attribute setup

Change the identity mapping with the requested attribute first, before
we setup the virtual memory mapping with the new requested attribute.

This makes sure that there is no window when identity map'ed attribute
may disagree with ioremap range on the attribute type.

This also avoids doing cpa on the ioremap'ed address twice (first in
ioremap_page_range and then in ioremap_change_attr using vaddr), and
should improve ioremap performance a bit.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20090409212708.373330000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>