PNP: add pnp_possible_config() -- can a device could be configured this way?

As part of a heuristic to identify modem devices, 8250_pnp.c
checks to see whether a device can be configured at any of the
legacy COM port addresses.

This patch moves the code that traverses the PNP "possible resource
options" from 8250_pnp.c to the PNP subsystem.  This encapsulation
is important because a future patch will change the implementation
of those resource options.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/include/linux/pnp.h b/include/linux/pnp.h
index dfaa567..e033e1b 100644
--- a/include/linux/pnp.h
+++ b/include/linux/pnp.h
@@ -479,6 +479,8 @@
 extern struct list_head pnp_cards;
 
 /* resource management */
+int pnp_possible_config(struct pnp_dev *dev, int type, resource_size_t base,
+			resource_size_t size);
 int pnp_auto_config_dev(struct pnp_dev *dev);
 int pnp_start_dev(struct pnp_dev *dev);
 int pnp_stop_dev(struct pnp_dev *dev);
@@ -506,6 +508,9 @@
 static inline void pnp_unregister_card_driver(struct pnp_card_driver *drv) { }
 
 /* resource management */
+static inline int pnp_possible_config(struct pnp_dev *dev, int type,
+				      resource_size_t base,
+				      resource_size_t size) { return 0; }
 static inline int pnp_auto_config_dev(struct pnp_dev *dev) { return -ENODEV; }
 static inline int pnp_start_dev(struct pnp_dev *dev) { return -ENODEV; }
 static inline int pnp_stop_dev(struct pnp_dev *dev) { return -ENODEV; }