REORG: mworker: move IPC functions to mworker.c

Move the following functions to mworker.c:

void mworker_accept_wrapper(int fd);
void mworker_pipe_register();
diff --git a/include/proto/mworker.h b/include/proto/mworker.h
index 87cbdd4..25d8c8c 100644
--- a/include/proto/mworker.h
+++ b/include/proto/mworker.h
@@ -20,4 +20,7 @@
 void mworker_block_signals();
 void mworker_unblock_signals();
 
+void mworker_accept_wrapper(int fd);
+void mworker_pipe_register();
+
 #endif /* PROTO_MWORKER_H_ */