resources.conf: Set UHD identifiers on B200 devices

osmo-trx-uhd uses these args during device search/selection process. As
those were not set until now for B200, it means when a B200 was used by
osmo-gsm-tester any UHD device could be picked up and used by UHD.
That was actually happening since inclusion of UmTRX devices in Prod
setup, when running tests against desired B200, actually the UmTRX
device was being used.

Change-Id: I696bbc800b05fdd9a68a77f363d76dcc53ef24ee
diff --git a/example/resources.conf.rnd b/example/resources.conf.rnd
index dc0251a..0fad50f 100644
--- a/example/resources.conf.rnd
+++ b/example/resources.conf.rnd
@@ -32,6 +32,7 @@
     multi_arfcn: true
     remote_user: jenkins
     trx_ip: 127.0.0.1
+    dev_args: "type=b200,serial=30A9FFB"
   ciphers: [a5_0, a5_1]
 
 - label: NanoBTS-ONW-1900