dm: migrate the dm_warn to use the log macro

Migrate the dm_warn function to log macro with
LOGC_DM category and LOGL_WARNING level.

This macro allows filtering with log command and allows
output on all log backend.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/core/util.c b/drivers/core/util.c
index 91e93b0..5be4ee7 100644
--- a/drivers/core/util.c
+++ b/drivers/core/util.c
@@ -11,17 +11,6 @@
 #include <linux/libfdt.h>
 #include <vsprintf.h>
 
-#if CONFIG_IS_ENABLED(DM_WARN)
-void dm_warn(const char *fmt, ...)
-{
-	va_list args;
-
-	va_start(args, fmt);
-	vprintf(fmt, args);
-	va_end(args);
-}
-#endif
-
 int list_count_items(struct list_head *head)
 {
 	struct list_head *node;
diff --git a/include/dm/util.h b/include/dm/util.h
index 138893c..c634e47 100644
--- a/include/dm/util.h
+++ b/include/dm/util.h
@@ -7,7 +7,7 @@
 #define __DM_UTIL_H
 
 #if CONFIG_IS_ENABLED(DM_WARN)
-void dm_warn(const char *fmt, ...);
+#define dm_warn(fmt...) log(LOGC_DM, LOGL_WARNING, ##fmt)
 #else
 static inline void dm_warn(const char *fmt, ...)
 {