usb ethernet gadget: split CDC Subset function

This is a simple "CDC Subset" (and MCCI "SAFE") function driver, extracted
from the all-in-one Ethernet gadget driver.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/Makefile

@@ -25,7 +25,7 @@ obj-$(CONFIG_USB_M66592)	+= m66592-udc.o
 C_UTILS =	composite.o usbstring.o config.o epautoconf.o
 
 g_zero-objs			:= zero.o f_sourcesink.o f_loopback.o $(C_UTILS)
-g_ether-objs			:= ether.o u_ether.o $(C_UTILS)
+g_ether-objs			:= ether.o u_ether.o f_subset.o $(C_UTILS)
 g_serial-objs			:= serial.o u_serial.o f_acm.o f_serial.o $(C_UTILS)
 g_midi-objs			:= gmidi.o usbstring.o config.o epautoconf.o
 gadgetfs-objs			:= inode.o

drivers/usb/gadget/u_ether.h

@@ -80,4 +80,7 @@ void gether_cleanup(void);
 struct net_device *gether_connect(struct gether *);
 void gether_disconnect(struct gether *);
 
+/* each configuration may bind one instance of an ethernet link */
+int geth_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN]);
+
 #endif /* __U_ETHER_H */