Make tests work on public repo as well

PUBLISHED_FROM=78acb18d597b6f47f31da13087fa6685f21ce445

src/common/platforms/nrf5/nrf5_libc.c

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2014-2016 Cesanta Software Limited
+ * All rights reserved
+ */
+
+#if (CS_PLATFORM == CS_P_NRF51 || CS_PLATFORM == CS_P_NRF52) && \
+    defined(__ARMCC_VERSION)
+int gettimeofday(struct timeval *tp, void *tzp) {
+  /* TODO */
+  tp->tv_sec = 0;
+  tp->tv_usec = 0;
+  return 0;
+}
+#endif