USB: Move configuration parsing code from usb.c to config.c

drivers/usb/core/Makefile

@@ -2,9 +2,10 @@
 # Makefile for USB Core files and filesystem
 #
 
-export-objs	:= usb.o hcd.o urb.o message.o 
+export-objs	:= usb.o hcd.o urb.o message.o config.o
 
-usbcore-objs	:= usb.o usb-debug.o hub.o hcd.o urb.o message.o 
+usbcore-objs	:= usb.o usb-debug.o hub.o hcd.o urb.o message.o \
+			config.o
 
 ifeq ($(CONFIG_USB_DEVICEFS),y)
 	usbcore-objs	+= devio.o inode.o drivers.o devices.o