[core] Update ltchiptool to fix realtek-ambz OTA issue

platform.json

@@ -127,7 +127,7 @@
     },
     "tool-ltchiptool": {
       "type": "uploader",
-      "version": "https://github.com/libretuya/ltchiptool#v1.5.4",
+      "version": "https://github.com/libretuya/ltchiptool#v1.6.0",
       "note": "This is used only for C/C++ code from ltchiptool."
     },
     "tool-openocd": {

platform.py

@@ -23,7 +23,7 @@ def check_ltchiptool():
     import ltchiptool
 
     importlib.reload(ltchiptool)
-    if Version(ltchiptool.get_version()) < Version("1.5.4"):
+    if Version(ltchiptool.get_version()) < Version("1.6.0"):
         raise ImportError("Version too old")