USB: ftdi_sio: new device id for papouch AD4USB

added new device pid (PAPOUCH_AD4USB_PID) to ftdi_sio.h and ftdi_sio.c

AD4USB measuring converter is a 4-input A/D converter which enables the
user to measure to four current inputs ranging from 0(4) to 20 mA or
voltage between 0 and 10 V. The measured values are then transferred to
a superior system in digital form. The AD4USB communicates via USB.
Powered is also via USB.  datasheet in english is here:
http://www.papouch.com/shop/scripts/pdf/ad4usb_en.pdf


Signed-off-by: Radek Liboska <liboska@uochb.cas.cz>

diff --git a/drivers/usb/serial/ftdi_sio_ids.h b/drivers/usb/serial/ftdi_sio_ids.h
index da92b49..2478130 100644
--- a/drivers/usb/serial/ftdi_sio_ids.h
+++ b/drivers/usb/serial/ftdi_sio_ids.h
@@ -968,6 +968,7 @@
 #define PAPOUCH_VID			0x5050	/* Vendor ID */
 #define PAPOUCH_TMU_PID			0x0400	/* TMU USB Thermometer */
 #define PAPOUCH_QUIDO4x4_PID		0x0900	/* Quido 4/4 Module */
+#define PAPOUCH_AD4USB_PID		0x8003	/* AD4USB Measurement Module */
 
 /*
  * Marvell SheevaPlug