Set the build configuration for NRF52 to small.

pan- · pan- · commit d3d6c8144db4 · 2016-07-26T23:34:46.000+01:00
diff --git a/hal/targets.json b/hal/targets.json
@@ -1951,7 +1951,8 @@
                 "value": "NRF_LF_SRC_XTAL",
                 "macro_name": "MBED_CONF_NORDIC_NRF_LF_CLOCK_SRC"
             }
-        }
+        },
+        "default_build": "small"
     },
     "NRF52_DK": {
         "supported_form_factors": ["ARDUINO"],
