USB: serial: add Fintek F81232 usb to serial driver

This is the first cut at a driver for the Fintek F81232 USB to serial
single port converter.  This provides the initial framework for the
device, and some data can move through it, but no line settings are
handled, so it's not that useful yet.  It does give people a starting
place to work from.

Thank to Fintek for providing samples and specifications, without which,
this driver would have never been able to be written.

Cc: Amanda Ying <Amanda_Ying@fintek.com.tw>
Cc: Tom Tsai <Tom_Tsai@fintek.com.tw>
Cc: <linux-usb@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/serial/Kconfig b/drivers/usb/serial/Kconfig
index 677f577..434df7f 100644
--- a/drivers/usb/serial/Kconfig
+++ b/drivers/usb/serial/Kconfig
@@ -238,6 +238,15 @@
 	  To compile this driver as a module, choose M here: the
 	  module will be called io_ti.
 
+config USB_SERIAL_F81232
+	tristate "USB Fintek F81232 Single Port Serial Driver"
+	help
+	  Say Y here if you want to use the Fintek F81232 single
+	  port usb to serial adapter.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called f81232.
+
 config USB_SERIAL_GARMIN
        tristate "USB Garmin GPS driver"
        help