usb: net: introduce support for Moschip USB ethernet

introduce an 'mcs7830' driver for Moschip MCS7830 based (7730/7830/7832)
USB 2.0 Ethernet Devices

see "MCS7830 -- USB 2.0 to 10/100M Fast Ethernet Controller" at
http://www.asix.com.tw/products.php?op=pItemdetail&PItemID=109;74;109

the driver was implemented based on the U-Boot Asix driver with
additional information gathered from the Moschip Linux driver,
development was done on "Delock 61147" and "Logilink UA0025C" dongles

Signed-off-by: Gerhard Sittig <gsi@denx.de>
Acked-by: Marek Vasut <marex@denx.de>
diff --git a/drivers/usb/eth/Makefile b/drivers/usb/eth/Makefile
index 03f5474..94551c4 100644
--- a/drivers/usb/eth/Makefile
+++ b/drivers/usb/eth/Makefile
@@ -8,4 +8,5 @@
 ifdef CONFIG_USB_ETHER_ASIX
 obj-y += asix.o
 endif
+obj-$(CONFIG_USB_ETHER_MCS7830) += mcs7830.o
 obj-$(CONFIG_USB_ETHER_SMSC95XX) += smsc95xx.o