Add stubs so that portduino can build with wifi. cc @mc-hamster

platformio.ini

@@ -253,7 +253,7 @@ lib_deps =
 ; The Portduino based sim environment on top of linux
 [env:linux]
 platform = https://github.com/geeksville/platform-portduino.git
-src_filter = ${env.src_filter} -<esp32/> -<nimble/> -<nrf52/>
+src_filter = ${env.src_filter} -<esp32/> -<nimble/> -<nrf52/> -<meshwifi/>
 build_flags = ${arduino_base.build_flags} -O0
 framework = arduino
 board = linux_x86_64

src/portduino/wifi-stubs.cpp

@@ -0,0 +1 @@
+../nrf52/wifi-stubs.cpp