[IA64] Ignore disabled Local SAPIC Affinity Structure in SRAT

According to the ACPI spec, the OSPM must ignore the contents of the
Processor Local APIC/SAPIC Affinity Structure in System Resource
Affinity Table (SRAT), if its enable flag is cleared. However, ia64
linux refers all of the Processor Local APIC/SAPIC Affinity Structures
in SRAT regardless of the enable flag. This is obviously against the
ACPI spec. This patch fixes this bug.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>