USB: add USB serial mos7720 driver

Add support for Moschip 7720 USB dual port usb to serial device.

This driver is originally based on the drivers/usb/io_edgeport.c driver.

Cleaned up and forward ported by me.

Cc: VijayaKumar <vijaykumar@aspirecom.net>
Cc: AjayKumar <ajay@aspirecom.net>
Cc: Gurudeva <gurudev@aspirecom.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/serial/Makefile b/drivers/usb/serial/Makefile
index 8dce833..a5047dc 100644
--- a/drivers/usb/serial/Makefile
+++ b/drivers/usb/serial/Makefile
@@ -34,6 +34,7 @@
 obj-$(CONFIG_USB_SERIAL_KLSI)			+= kl5kusb105.o
 obj-$(CONFIG_USB_SERIAL_KOBIL_SCT)		+= kobil_sct.o
 obj-$(CONFIG_USB_SERIAL_MCT_U232)		+= mct_u232.o
+obj-$(CONFIG_USB_SERIAL_MOS7720)		+= mos7720.o
 obj-$(CONFIG_USB_SERIAL_MOS7840)		+= mos7840.o
 obj-$(CONFIG_USB_SERIAL_NAVMAN)			+= navman.o
 obj-$(CONFIG_USB_SERIAL_OMNINET)		+= omninet.o