smsc75xx: SMSC LAN75xx USB gigabit ethernet adapter driver

This patch adds a driver for SMSC's LAN7500 family of USB 2.0
to gigabit ethernet adapters.  It's loosely based on the smsc95xx
driver but the device registers for LAN7500 are completely different.

Signed-off-by: Steve Glendinning <steve.glendinning@smsc.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/Makefile

@@ -11,6 +11,7 @@ obj-$(CONFIG_USB_NET_AX8817X)	+= asix.o
 obj-$(CONFIG_USB_NET_CDCETHER)	+= cdc_ether.o
 obj-$(CONFIG_USB_NET_CDC_EEM)	+= cdc_eem.o
 obj-$(CONFIG_USB_NET_DM9601)	+= dm9601.o
+obj-$(CONFIG_USB_NET_SMSC75XX)	+= smsc75xx.o
 obj-$(CONFIG_USB_NET_SMSC95XX)	+= smsc95xx.o
 obj-$(CONFIG_USB_NET_GL620A)	+= gl620a.o
 obj-$(CONFIG_USB_NET_NET1080)	+= net1080.o