Enlarge LPTICKER_DELAY_TICKS for safe

On Nuvoton targets, lp_ticker_set_interrupt(...) needs around 3 lp-ticker
ticks to take effect. It may miss when current tick and match tick are very
close (see hal/LowPowerTickerWrapper.cpp). Enlarge LPTICKER_DELAY_TICKS to
4 from 3 to address this boundary case.

Author: ccli8

targets/targets.json

@@ -8841,7 +8841,7 @@
         ],
         "macros_add": [
             "MBED_FAULT_HANDLER_DISABLED",
-            "LPTICKER_DELAY_TICKS=3"
+            "LPTICKER_DELAY_TICKS=4"
         ],
         "supported_toolchains": ["ARMC6", "GCC_ARM", "IAR"],
         "config": {