Fix mbed_hal-watchdog failing with OOM

ccli8 · ccli8 · commit 81dd2aa7875f · 2019-07-10T14:32:03.000+08:00
This is to fix OOM error on targets with just 16KiB RAM.
diff --git a/TESTS/mbed_hal/watchdog/main.cpp b/TESTS/mbed_hal/watchdog/main.cpp
@@ -69,7 +69,7 @@ using utest::v1::Harness;
 
 const watchdog_config_t WDG_CONFIG_DEFAULT = { .timeout_ms = WDG_TIMEOUT_MS };
 
-Thread wdg_kicking_thread;
+Thread wdg_kicking_thread(osPriorityNormal, 768);
 Semaphore kick_wdg_during_test_teardown(0, 1);
 
 void wdg_kicking_thread_fun()
