Relocate protocol files within tmk_core/common/ (#14972)

* Relocate non platform files within tmk_core/common/

* clang

tmk_core/protocol/usb_util.h

@@ -0,0 +1,22 @@
+/* Copyright 2021 QMK
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+
+#include <stdbool.h>
+
+void usb_disconnect(void);
+bool usb_connected_state(void);
+bool usb_vbus_state(void);