feat(common/debug): add new macro ERROR_NL() to print just a newline

Existing macro ERROR() prints string "ERROR" followed by string
specified by caller. Therefore via this existing macro it is not
possible to end incomplete / existing line by a newline character.

This change adds a new macro ERROR_NL() which prints just a newline
character without any prefix. Implementation of this macro is done via a
new function tf_log_newline() which based on supplied log level either
return or print newline character.

If needed in future based on this tf_log_newline() function can be
defined also macros for other log levels.

Signed-off-by: Pali Rohár <pali@kernel.org>
Change-Id: I05414ca177f94cdc0f6077394d9c4af4a4382306
diff --git a/common/tf_log.c b/common/tf_log.c
index 08d3cf4..68f1be4 100644
--- a/common/tf_log.c
+++ b/common/tf_log.c
@@ -49,6 +49,20 @@
 	va_end(args);
 }
 
+void tf_log_newline(const char log_fmt[2])
+{
+	unsigned int log_level = log_fmt[0];
+
+	/* Verify that log_level is one of LOG_MARKER_* macro defined in debug.h */
+	assert((log_level > 0U) && (log_level <= LOG_LEVEL_VERBOSE));
+	assert((log_level % 10U) == 0U);
+
+	if (log_level > max_log_level)
+		return;
+
+	putchar('\n');
+}
+
 /*
  * The helper function to set the log level dynamically by platform. The
  * maximum log level is determined by `LOG_LEVEL` build flag at compile time