Add concept of system bus, so system devices (CPUs, PICs, etc) can have a...

Add concept of system bus, so system devices (CPUs, PICs, etc) can have a common home in the device tree.
Add helper functions for {un,}registering.

drivers/base/Makefile

 O_TARGET	:= base.o
 
-obj-y		:= core.o interface.o fs.o
+obj-y		:= core.o sys.o interface.o fs.o
 
-export-objs	:= core.o interface.o fs.o 
+export-objs	:= core.o sys.o interface.o fs.o 
 
 include $(TOPDIR)/Rules.make

include/linux/device.h

@@ -143,4 +143,8 @@ static inline void get_device(struct device * dev)
 
 extern void put_device(struct device * dev);
 
+/* drivers/base/sys.c */
+extern int register_sys_device(struct device * dev);
+extern void unregister_sys_device(struct device * dev);
+
 #endif /* _DEVICE_H_ */