Merge pull request #12874 from LDong-Arm/nrf52_stack_size

nRF: use Mbed-default boot-stack-size & fix stack_size_unification test

Author: 0xc0170

TESTS/mbed_hal/stack_size_unification/main.cpp

@@ -31,10 +31,7 @@ extern osThreadAttr_t _main_thread_attr;
 #endif
 extern uint32_t mbed_stack_isr_size;
 
-/* Exception for Nordic boards - BLE requires 2KB ISR stack. */
-#if defined(TARGET_NRF5x)
-#define EXPECTED_ISR_STACK_SIZE                  (2048)
-#elif !defined(MBED_CONF_RTOS_PRESENT)
+#if !defined(MBED_CONF_RTOS_PRESENT)
 #define EXPECTED_ISR_STACK_SIZE                  (4096)
 #else
 #define EXPECTED_ISR_STACK_SIZE                  (1024)

rtos/source/TARGET_CORTEX/mbed_lib.json

@@ -76,18 +76,6 @@
         "STM32F072RB": {
             "main-thread-stack-size": 3072
         },
-        "MCU_NRF51": {
-            "target.boot-stack-size": "0x800"
-        },
-        "MCU_NRF52840": {
-            "target.boot-stack-size": "0x800"
-        },
-        "MCU_NRF52832": {
-            "target.boot-stack-size": "0x800"
-        },
-        "MCU_NRF51_UNIFIED": {
-            "target.boot-stack-size": "0x800"
-        },
         "NUVOTON": {
             "idle-thread-stack-size-debug-extra": 512
         }