Enable default Mesh interface on KW24D

This device still requires MCR20A driver to be in build tree
and this patch PelionIoT/mcr20a-rf-driver#18

Author: Seppo Takalo

targets/targets.json

@@ -582,10 +582,13 @@
         "macros": ["CPU_MKW24D512VHA5", "FSL_RTOS_MBED"],
         "inherits": ["Target"],
         "detect_code": ["0250"],
-        "device_has": ["USTICKER", "LPTICKER", "RTC", "ANALOGIN", "I2C", "I2CSLAVE", "INTERRUPTIN", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "SERIAL", "SERIAL_FC", "SLEEP", "SPI", "SPISLAVE", "STDIO_MESSAGES", "TRNG", "FLASH"],
+        "device_has": ["USTICKER", "LPTICKER", "RTC", "ANALOGIN", "I2C", "I2CSLAVE", "INTERRUPTIN", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "SERIAL", "SERIAL_FC", "SLEEP", "SPI", "SPISLAVE", "STDIO_MESSAGES", "TRNG", "FLASH", "802_15_4_PHY"],
         "release_versions": ["2", "5"],
         "device_name": "MKW24D512xxx5",
-        "bootloader_supported": true
+        "bootloader_supported": true,
+        "overrides": {
+            "network-default-interface-type": "MESH"
+        }
     },
     "KW41Z": {
         "supported_form_factors": ["ARDUINO"],