printk: add pr_devel_once and pr_devel_ratelimited

Standardize pr_devel logging macros family by adding pr_devel_once and
pr_devel_ratelimited.
Signed-off-by: Mikhail Gruzdev <michail.gruzdev@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/printk.h

@@ -252,6 +252,15 @@ extern void dump_stack(void) __cold;
 	printk_once(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 #define pr_cont_once(fmt, ...)					\
 	printk_once(KERN_CONT pr_fmt(fmt), ##__VA_ARGS__)
+
+#if defined(DEBUG)
+#define pr_devel_once(fmt, ...)					\
+	printk_once(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
+#else
+#define pr_devel_once(fmt, ...)					\
+	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
+#endif
+
 /* If you are writing a driver, please use dev_dbg instead */
 #if defined(DEBUG)
 #define pr_debug_once(fmt, ...)					\
@@ -295,6 +304,15 @@ extern void dump_stack(void) __cold;
 #define pr_info_ratelimited(fmt, ...)					\
 	printk_ratelimited(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 /* no pr_cont_ratelimited, don't do that... */
+
+#if defined(DEBUG)
+#define pr_devel_ratelimited(fmt, ...)					\
+	printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
+#else
+#define pr_devel_ratelimited(fmt, ...)					\
+	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
+#endif
+
 /* If you are writing a driver, please use dev_dbg instead */
 #if defined(DEBUG)
 #define pr_debug_ratelimited(fmt, ...)					\