[M252KG] Enlarge required deep sleep latency

ccli8 · ccli8 · commit a5afcd61152a · 2019-09-27T17:45:53.000+08:00
This configuration is to pass wake-up from deep-sleep test such as mbedmicro-rtos-mbed-systimer.
diff --git a/targets/targets.json b/targets/targets.json
@@ -8819,6 +8819,7 @@
         },
         "overrides": {
             "mpu-rom-end": "0x1fffffff",
+            "deep-sleep-latency": 1,
             "tickless-from-us-ticker": true
         },
         "inherits": ["Target"],
