change to own USB vendor/device ID

we shouldn't re-use the vendor/device ID usd by simtrace1, as the
protocol is incompatible and applications for simtrace 1 don't work with
simtrace2.   Also, there's a different processor architecutre in the
hardware.
diff --git a/usb_application/simtrace.py b/usb_application/simtrace.py
index cf77e21..48fd73a 100755
--- a/usb_application/simtrace.py
+++ b/usb_application/simtrace.py
@@ -12,7 +12,7 @@
 import time
 
 def find_dev():
-    dev = usb.core.find(idVendor=0x16c0, idProduct=0x0762)
+    dev = usb.core.find(idVendor=0x1d50, idProduct=0x60e3)
     if dev is None:
         raise ValueError("Device not found")
     else: