Added NO_IOAPIC_CHECK in io_apic_get_unique_id() for ACPI boot

diff -puN arch/i386/kernel/io_apic.c~no-ioapic-check arch/i386/kernel/io_apic.c
@@ -2436,13 +2436,18 @@ int __init io_apic_get_unique_id (int io
 	unsigned long flags;
 	int i = 0;
 
+	/* Don't check I/O APIC IDs for some xAPIC systems.  They have
+	 * no meaning without the serial APIC bus. 
+	 */
+
+	if (NO_IOAPIC_CHECK)
+		return apic_id;
+
 	/*
 	 * The P4 platform supports up to 256 APIC IDs on two separate APIC 
 	 * buses (one for LAPICs, one for IOAPICs), where predecessors only 
 	 * supports up to 16 on one shared APIC bus.
 	 * 
-	 * TBD: Expand LAPIC/IOAPIC support on P4-class systems to take full
-	 *      advantage of new APIC bus architecture.
 	 */
 
 	if (physids_empty(apic_id_map))