USB: ftdi driver pid for dmx-interfaces

Please add a usb pid to the ftdi_sio driver. The pid is used by dmx4all
dmx-interfaces (for stage lighting).

The interfaces are using the usb-id 0403:c850. I added the id to the driver
and it works perfectly. I added a patch for linux 2.6.18.1, too.

From: Frank Sievertsen <frank@sievertsen.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/ftdi_sio.c

@@ -311,6 +311,7 @@ static struct usb_device_id id_table_combined [] = {
 	{ USB_DEVICE(FTDI_VID, FTDI_ACTZWAVE_PID) },
 	{ USB_DEVICE(FTDI_VID, FTDI_IRTRANS_PID) },
 	{ USB_DEVICE(FTDI_VID, FTDI_IPLUS_PID) },
+	{ USB_DEVICE(FTDI_VID, FTDI_DMX4ALL) },
 	{ USB_DEVICE(FTDI_VID, FTDI_SIO_PID) },
 	{ USB_DEVICE(FTDI_VID, FTDI_8U232AM_PID) },
 	{ USB_DEVICE(FTDI_VID, FTDI_8U232AM_ALT_PID) },

drivers/usb/serial/ftdi_sio.h

@@ -55,6 +55,9 @@
 /* iPlus device */
 #define FTDI_IPLUS_PID 0xD070 /* Product Id */
 
+/* DMX4ALL DMX Interfaces */
+#define FTDI_DMX4ALL 0xC850
+
 /* www.crystalfontz.com devices - thanx for providing free devices for evaluation ! */
 /* they use the ftdi chipset for the USB interface and the vendor id is the same */
 #define FTDI_XF_632_PID 0xFC08	/* 632: 16x2 Character Display */