test: log functions with CONFIG_LOG=n

If CONFIG_LOG=n, we still expect output for log_err(), log_warning(),
log_notice(), log_info() and in case of DEBUG=1 also for log_debug().

Provide unit tests verifying this.

The tests depend on:

	CONFIG_CONSOLE_RECORD=y
	CONFIG_LOG=n
	CONFIG_UT_LOG=y

It may be necessary to increase the value of CONFIG_SYS_MALLOC_F_LEN to
accommodate CONFIG_CONSOLE_RECORD=y.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/include/test/log.h b/include/test/log.h
new file mode 100644
index 0000000..c661cde
--- /dev/null
+++ b/include/test/log.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2020, Heinrich Schuchardt <xypron.glpk@gmx.de>
+ *
+ * Tests for logging functions
+ */
+
+#ifndef __TEST_LOG_H__
+#define __TEST_LOG_H__
+
+#include <test/test.h>
+
+/* Declare a new logging test */
+#define LOG_TEST(_name) UNIT_TEST(_name, 0, log_test)
+
+#endif /* __TEST_LOG_H__ */