ACPI: Use ioremap_cache()

Although the temporary boot-time ACPI table mappings
were set up with CPU caching enabled, the permanent table
mappings and AML run-time region memory accesses were
set up with ioremap(), which on x86 is a synonym for
ioremap_nocache().

Changing this to ioremap_cache() improves performance as
seen when accessing the tables via acpidump,
or /sys/firmware/acpi/tables.  It should also improve
AML run-time performance.

No change on ia64.

Reported-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>