add treebench app

src/app/treebench/Kconfig

+# Copyright 2020 Daniel Friesel
+#
+# SPDX-License-Identifier: CC0-1.0
+
+prompt "Tree Evaluation Benchmark"
+depends on loop && !wakeup

src/app/treebench/Makefile.inc

+# vim:ft=make
+#
+# Copyright 2020 Daniel Friesel
+#
+# SPDX-License-Identifier: CC0-1.0
+
+ifdef app
+	loop = 1
+endif

src/app/treebench/main.cc

+/*
+ * Copyright 2020 Daniel Friesel
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+#include "arch.h"
+#include "driver/gpio.h"
+#include "driver/stdout.h"
+#include "driver/uptime.h"
+#include "driver/counter.h"
+
+#include "tree.c.inc"
+
+void loop(void)
+{
+	counter.start();
+	counter.stop();
+	kout << "nop @ " << counter.value << "/" << counter.overflow << " cycles" << endl << endl;
+
+	run_benchmark();
+}
+
+int main(void)
+{
+	arch.setup();
+	gpio.setup();
+	kout.setup();
+
+	arch.idle_loop();
+
+	return 0;
+}