py/usermod.cmake: If USER_C_MODULES is a folder add micropython.cmake.

This mirrors how it works when using a Makefile.

Signed-off-by: Andrew Leech <andrew.leech@planetinnovation.com.au>

py/usermod.cmake

@@ -42,6 +42,10 @@ endfunction()
 # Include CMake files for user modules.
 if (USER_C_MODULES)
     foreach(USER_C_MODULE_PATH ${USER_C_MODULES})
+        # If a directory is given, append the micropython.cmake to it.
+        if (IS_DIRECTORY ${USER_C_MODULE_PATH})
+            set(USER_C_MODULE_PATH "${USER_C_MODULE_PATH}/micropython.cmake")
+        endif()
         # Confirm the provided path exists, show abspath if not to make it clearer to fix.
         if (NOT EXISTS ${USER_C_MODULE_PATH})
             get_filename_component(USER_C_MODULES_ABS "${USER_C_MODULE_PATH}" ABSOLUTE)