PNP: make generic pnp_add_irq_resource()

Add a pnp_add_irq_resource() that can be used by all the PNP
backends.  This consolidates a little more pnp_resource_table
knowledge into one place.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/pnp/base.h b/drivers/pnp/base.h
index 7867357..3dd5d84 100644
--- a/drivers/pnp/base.h
+++ b/drivers/pnp/base.h
@@ -40,3 +40,6 @@
 	struct pnp_resource dma[PNP_MAX_DMA];
 	struct pnp_resource irq[PNP_MAX_IRQ];
 };
+
+struct pnp_resource *pnp_add_irq_resource(struct pnp_dev *dev, int irq,
+					  int flags);