USB: add ZyXEL vendor/product ID to rtl8150 driver

I just got a "ZyXEL Prestige USB Adapter" that is actually RTL8150
adapter.  Here is the relevant /proc/bus/usb/devices output (after
adding the vendor/product IDs to the driver):

T:  Bus=01 Lev=02 Prnt=02 Port=02 Cnt=02 Dev#=119 Spd=12  MxCh= 0
D:  Ver= 1.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs=  1
P:  Vendor=0586 ProdID=401a Rev= 1.00
S:  Manufacturer=ZyXEL
S:  Product=Prestige USB Adapter
S:  SerialNumber=1027
C:* #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=120mA
I:  If#= 0 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=ff Driver=rtl8150
E:  Ad=81(I) Atr=02(Bulk) MxPS=  64 Ivl=0ms
E:  Ad=02(O) Atr=02(Bulk) MxPS=  64 Ivl=0ms
E:  Ad=83(I) Atr=03(Int.) MxPS=   8 Ivl=1ms

This patch adds the ZyXEL vendor ID to the rtl8150.c driver.  The
device has absolutely no identifying marks on the outside for model
type, just a serial number, and I can't find anything on ZyXEL's
website, so I called the product ID PRODUCT_ID_PRESTIGE to match the
product string.
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

drivers/usb/net/rtl8150.c

@@ -129,11 +129,13 @@
 #define	VENDOR_ID_MELCO			0x0411
 #define VENDOR_ID_MICRONET		0x3980
 #define	VENDOR_ID_LONGSHINE		0x07b8
+#define	VENDOR_ID_ZYXEL			0x0586
 
 #define PRODUCT_ID_RTL8150		0x8150
 #define	PRODUCT_ID_LUAKTX		0x0012
 #define	PRODUCT_ID_LCS8138TX		0x401a
 #define PRODUCT_ID_SP128AR		0x0003
+#define	PRODUCT_ID_PRESTIGE		0x401a
 
 #undef	EEPROM_WRITE
 
@@ -143,6 +145,7 @@ static struct usb_device_id rtl8150_table[] = {
 	{USB_DEVICE(VENDOR_ID_MELCO, PRODUCT_ID_LUAKTX)},
 	{USB_DEVICE(VENDOR_ID_MICRONET, PRODUCT_ID_SP128AR)},
 	{USB_DEVICE(VENDOR_ID_LONGSHINE, PRODUCT_ID_LCS8138TX)},
+	{USB_DEVICE(VENDOR_ID_ZYXEL, PRODUCT_ID_PRESTIGE)},
 	{}
 };