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/libcommon/proto.c

@@ -0,0 +1,51 @@
+// SPDX-FileCopyrightText: 2022 Tillitis AB <tillitis.se>
+// SPDX-License-Identifier: BSD-2-Clause
+
+#include <stddef.h>
+#include <stdint.h>
+#include <tkey/assert.h>
+#include <tkey/debug.h>
+#include <tkey/proto.h>
+#include <tkey/tk1_mem.h>
+
+uint8_t genhdr(uint8_t id, uint8_t endpoint, uint8_t status, enum cmdlen len)
+{
+	return (id << 5) | (endpoint << 3) | (status << 2) | len;
+}
+
+int parseframe(uint8_t b, struct frame_header *hdr)
+{
+	if ((b & 0x80) != 0) {
+		// Bad version
+		return -1;
+	}
+
+	if ((b & 0x4) != 0) {
+		// Must be 0
+		return -1;
+	}
+
+	hdr->id = (b & 0x60) >> 5;
+	hdr->endpoint = (b & 0x18) >> 3;
+
+	// Length
+	switch (b & 0x3) {
+	case LEN_1:
+		hdr->len = 1;
+		break;
+	case LEN_4:
+		hdr->len = 4;
+		break;
+	case LEN_32:
+		hdr->len = 32;
+		break;
+	case LEN_128:
+		hdr->len = 128;
+		break;
+	default:
+		// Unknown length
+		return -1;
+	}
+
+	return 0;
+}