bug.h: introduce WARN_ONCE

Add WARN_ONCE definition to allow single time notification
of warnings to the user.
Taken from Linux kernel (4.17) with slight changes
(Removed __section(.data.once))

Signed-off-by: Ramon Fried <ramon.fried@gmail.com>
[trini: Drop the musb and dwc3 compat versions]
Signed-off-by: Tom Rini <trini@konsulko.com>

include/linux/bug.h

@@ -20,6 +20,13 @@
 	unlikely(__ret_warn_on);					\
 })
 
+#define WARN(condition, format...) ({                   \
+	int __ret_warn_on = !!(condition);              \
+	if (unlikely(__ret_warn_on))                    \
+		printf(format);                  \
+	unlikely(__ret_warn_on);                    \
+})
+
 #define WARN_ON_ONCE(condition)	({				\
 	static bool __warned;					\
 	int __ret_warn_once = !!(condition);			\
@@ -31,4 +38,15 @@
 	unlikely(__ret_warn_once);				\
 })
 
+#define WARN_ONCE(condition, format...) ({          \
+	static bool __warned;     \
+	int __ret_warn_once = !!(condition);            \
+								\
+	if (unlikely(__ret_warn_once && !__warned)) {       \
+		__warned = true;                \
+		WARN(1, format);                \
+	}                           \
+	unlikely(__ret_warn_once);              \
+})
+
 #endif	/* _LINUX_BUG_H */