Add helper function to find a Local APIC by ID in the device tree.

Change-Id: Ie2d7d8e1f647a0c92d2de09e32454fbea688b1e7
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: http://review.coreboot.org/695
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
diff --git a/src/include/device/device.h b/src/include/device/device.h
index a7de0c9..c097f57 100644
--- a/src/include/device/device.h
+++ b/src/include/device/device.h
@@ -132,6 +132,7 @@
 device_t dev_find_class (unsigned int class, device_t from);
 device_t dev_find_slot (unsigned int bus, unsigned int devfn);
 device_t dev_find_slot_on_smbus (unsigned int bus, unsigned int addr);
+device_t dev_find_lapic(unsigned apic_id);
 
 /* Debug functions */
 void print_resource_tree(struct device * root, int debug_level,