USB: pl2303: another product ID

I've just got a USB GPRS/EDGE modem branded Manufacturer Micromax Model
MMX610U (see http://www.airtel.in/level2_t3data.aspx?path=1/106/179)
working by adding another product ID to pl2303.  Modem info reports same
module as  Max Arnold's i.e.SIMCOM SIM600  but  with product ID 0x0612
(cf Ox0611).

From: Steve Murphy <steve@gnusis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/serial/pl2303.h b/drivers/usb/serial/pl2303.h
index 3bdefe0..cff160a 100644
--- a/drivers/usb/serial/pl2303.h
+++ b/drivers/usb/serial/pl2303.h
@@ -14,6 +14,7 @@
 #define PL2303_PRODUCT_ID_PHAROS	0xaaa0
 #define PL2303_PRODUCT_ID_RSAQ3		0xaaa2
 #define PL2303_PRODUCT_ID_ALDIGA	0x0611
+#define PL2303_PRODUCT_ID_MMX		0x0612
 
 #define ATEN_VENDOR_ID		0x0557
 #define ATEN_VENDOR_ID2		0x0547