USB: Driver for CH341 USB-serial adaptor

This patch implements a USB serial port driver for the Winchiphead
CH341 USB-RS232 Converter. This chip also implements an IEEE 1284
parallel port, I2C and SPI, but that is not supported by the driver.

Signed-off-by: Frank A Kingswood <frank@kingswood-consulting.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/Makefile

@@ -15,6 +15,7 @@ obj-$(CONFIG_USB_SERIAL_AIRCABLE)		+= aircable.o
 obj-$(CONFIG_USB_SERIAL_AIRPRIME)		+= airprime.o
 obj-$(CONFIG_USB_SERIAL_ARK3116)		+= ark3116.o
 obj-$(CONFIG_USB_SERIAL_BELKIN)			+= belkin_sa.o
+obj-$(CONFIG_USB_SERIAL_CH341)			+= ch341.o
 obj-$(CONFIG_USB_SERIAL_CP2101)			+= cp2101.o
 obj-$(CONFIG_USB_SERIAL_CYBERJACK)		+= cyberjack.o
 obj-$(CONFIG_USB_SERIAL_CYPRESS_M8)		+= cypress_m8.o