x86/mrst: Set ISA bus type for fake MP IRQs

We use MP IRQs for SFI presented timer interrupts, we should
also set mp_bus_not_pci for MP_ISA_BUS so that pin_2_irq mapping
is correct.
Signed-off-by: NJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: NDirk Brandewie <dirk.brandewie@gmail.com>
Link: http://lkml.kernel.org/n/tip-8h3rc1igpp8ir94aas69qmhk@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/apic/io_apic.c

@@ -1010,7 +1010,7 @@ static int pin_2_irq(int idx, int apic, int pin)
 	} else {
 		u32 gsi = gsi_cfg->gsi_base + pin;
 
-		if (gsi >= legacy_pic->nr_legacy_irqs)
+		if (gsi >= NR_IRQS_LEGACY)
 			irq = gsi;
 		else
 			irq = gsi_top + gsi;
@@ -3610,7 +3610,7 @@ static void __init probe_nr_irqs_gsi(void)
 {
 	int nr;
 
-	nr = gsi_top + legacy_pic->nr_legacy_irqs;
+	nr = gsi_top + NR_IRQS_LEGACY;
 	if (nr > nr_irqs_gsi)
 		nr_irqs_gsi = nr;