Added nuttx sim config.

cmake/configs/config_nuttx_sim_simple.cmake

@@ -0,0 +1,23 @@
+include(nuttx/px4_impl_nuttx)
+
+message(WARNING "this is a work in progress and doesn't build yet")
+
+function(px4_set_config_modules out_module_list)
+
+	set(config_module_list
+		platforms/nuttx
+		platforms/nuttx/px4_layer
+		platforms/common
+		drivers/led
+		drivers/device
+		modules/systemlib
+		modules/uORB
+		examples/px4_simple_app
+		lib/mathlib/math/filter
+		lib/conversion
+		)
+
+	set(${out_module_list} ${config_module_list} PARENT_SCOPE)
+
+endfunction()
+