srs/amarisoft{ue,enb}: Fix b200 specific rf_dev_args

Commit 12ae6d79a5b53a213f619999ef0230c1dae88bb7 switched the rf_dev_type
to be in lowercase but forgot to change these conditions.

Change-Id: I91d3877381b4e6343dc4aa0465e699341ed6648d
diff --git a/src/osmo_gsm_tester/srs_enb.py b/src/osmo_gsm_tester/srs_enb.py
index fe0e550..372848d 100644
--- a/src/osmo_gsm_tester/srs_enb.py
+++ b/src/osmo_gsm_tester/srs_enb.py
@@ -214,7 +214,7 @@
             config.overlay(values, dict(enb=dict(rf_dev_args=rf_dev_args)))
 
         # Set UHD frame size as a function of the cell bandwidth on B2XX
-        if self._conf.get('rf_dev_type') == 'UHD' and values['enb'].get('rf_dev_args', None) is not None:
+        if self._conf.get('rf_dev_type') == 'uhd' and values['enb'].get('rf_dev_args', None) is not None:
             if 'b200' in values['enb'].get('rf_dev_args'):
                 rf_dev_args = values['enb'].get('rf_dev_args', '')
                 rf_dev_args += ',' if rf_dev_args != '' and not rf_dev_args.endswith(',') else ''