usb: net: Add support for Microchip LAN75xx and LAN78xx

Add support for Microchip LAN7500, LAN7800 and LAN7850,
USB to 10/100/1000 Ethernet Controllers.

Signed-off-by: Yuiko Oshino <yuiko.oshino@microchip.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/drivers/usb/Kconfig b/drivers/usb/Kconfig
index da3ec2f..62126aa 100644
--- a/drivers/usb/Kconfig
+++ b/drivers/usb/Kconfig
@@ -94,4 +94,6 @@
 
 source "drivers/usb/gadget/Kconfig"
 
+source "drivers/usb/eth/Kconfig"
+
 endif