Merge pull request #2432 from recrof/kiss-radio-everywhere

kiss radio: added stm32 support + envs in platformio.ini

variants/thinknode_m6/platformio.ini

@@ -116,4 +116,9 @@ build_src_filter = ${ThinkNode_M6.build_src_filter}
 lib_deps =
   ${ThinkNode_M6.lib_deps}
   densaugeo/base64 @ ~1.4.0
-  end2endzone/NonBlockingRTTTL@^1.3.0
+  end2endzone/NonBlockingRTTTL@^1.3.0
+
+[env:ThinkNode_M6_kiss_modem]
+extends = ThinkNode_M6
+build_src_filter = ${ThinkNode_M6.build_src_filter}
+  +<../examples/kiss_modem/>