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

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

variants/promicro/platformio.ini

@@ -171,3 +171,8 @@ build_src_filter = ${Promicro.build_src_filter}
   +<../examples/simple_sensor>
 lib_deps =
   ${Promicro.lib_deps}
+
+[env:ProMicro_kiss_modem]
+extends = Promicro
+build_src_filter = ${Promicro.build_src_filter}
+  +<../examples/kiss_modem/>