fw: Import tkey-libs fw-2

This is an import of the fw-2 tag of tkey-libs.

We import the entire tkey-libs repo minus dot files into the
tillitis-key1 repo to make it very simple not to make mistakes
regarding which firmware tag depends on which tkey-libs tag,
especially considering locking down with NVCM.

Please see README for information about developing with another
tkey-libs or how to import future tkey-libs.

Since tkey-libs is now a part of the repo we also add tkey-libs to the
clean_fw target.

hw/application_fpga/tkey-libs/include/tkey/touch.h

@@ -0,0 +1,17 @@
+// SPDX-FileCopyrightText: 2023 Tillitis AB <tillitis.se>
+// SPDX-License-Identifier: BSD-2-Clause
+
+#ifndef TKEY_TOUCH_H
+#define TKEY_TOUCH_H
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <tkey/tk1_mem.h>
+
+// touchwait() waits for a touch event while blinking color on the
+// status LED. timeout_s is the timeout in seconds.
+//
+// If a touch event occurs it returns true. If the timeout expires it
+// returns false.
+bool touch_wait(int color, int timeout_s);
+#endif