embed: Fix arguments to mp_raw_code_load_mem.

Update arguments to mp_raw_code_load_mem so that the embed port can build
when MICROPY_PERSISTENT_CODE_LOAD is enabled.

ports/embed/port/embed_util.c

@@ -66,7 +66,9 @@ void mp_embed_exec_mpy(const uint8_t *mpy, size_t len) {
         // Execute the given .mpy data.
         mp_module_context_t *ctx = m_new_obj(mp_module_context_t);
         ctx->module.globals = mp_globals_get();
-        mp_compiled_module_t cm = mp_raw_code_load_mem(mpy, len, ctx);
+        mp_compiled_module_t cm;
+        cm.context = ctx;
+        mp_raw_code_load_mem(mpy, len, &cm);
         mp_obj_t f = mp_make_function_from_raw_code(cm.rc, ctx, MP_OBJ_NULL);
         mp_call_function_0(f);
         nlr_pop();