sparseirq: make some func to be used with genirq

Impact: clean up sparseirq fallout on random.c

Ingo suggested to change some ifdef from SPARSE_IRQ to GENERIC_HARDIRQS
so we could some #ifdef later if all arch support genirq

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/drivers/pci/intr_remapping.c b/drivers/pci/intr_remapping.c
index f78371b..3d60413 100644
--- a/drivers/pci/intr_remapping.c
+++ b/drivers/pci/intr_remapping.c
@@ -20,7 +20,7 @@
 	u8  irte_mask;
 };
 
-#ifdef CONFIG_SPARSE_IRQ
+#ifdef CONFIG_GENERIC_HARDIRQS
 static struct irq_2_iommu *get_one_free_irq_2_iommu(int cpu)
 {
 	struct irq_2_iommu *iommu;