Prepare mbed-tools release 5.3.0

Author: monty-bot

CHANGELOG.md

@@ -12,6 +12,15 @@ beta releases are not included in this history. For a full list of all releases,
 
 [//]: # (begin_release_notes)
 
+5.3.0 (2021-01-30)
+==================
+
+Features
+--------
+
+- Targets added: arm_mps2_m55. (#20210130050107)
+
+
 5.2.0 (2021-01-29)
 ==================
 

src/mbed_tools/targets/_internal/data/board_database_snapshot.json

@@ -187,6 +187,16 @@
         "mbed_os_support": [],
         "mbed_enabled": []
     },
+    {
+        "board_type": "ARM_MPS2_M55",
+        "board_name": "arm_mps2_m55",
+        "product_code": "5010",
+        "target_type": "platform",
+        "slug": "arm_mps2_m55",
+        "build_variant": [],
+        "mbed_os_support": [],
+        "mbed_enabled": []
+    },
     {
         "board_type": "TMPM4KN",
         "board_name": "SBK-M4KN development board",