OF: make of_property_for_each_{u32|string}() use parameters if OF is not enabled

I am getting a few
|warning: unused variable ‘p’ [-Wunused-variable]
|warning: unused variable ‘prop’ [-Wunused-variable]

in the case where CONFIG_OF is not defined and the parameters are only
used in the loop macro.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Grant Likely <grant.likely@linaro.org>

include/linux/of.h

@@ -323,12 +323,6 @@ extern int of_detach_node(struct device_node *);
  */
 const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
 			       u32 *pu);
-#define of_property_for_each_u32(np, propname, prop, p, u)	\
-	for (prop = of_find_property(np, propname, NULL),	\
-		p = of_prop_next_u32(prop, NULL, &u);		\
-		p;						\
-		p = of_prop_next_u32(prop, p, &u))
-
 /*
  * struct property *prop;
  * const char *s;
@@ -337,11 +331,6 @@ const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
  *         printk("String value: %s\n", s);
  */
 const char *of_prop_next_string(struct property *prop, const char *cur);
-#define of_property_for_each_string(np, propname, prop, s)	\
-	for (prop = of_find_property(np, propname, NULL),	\
-		s = of_prop_next_string(prop, NULL);		\
-		s;						\
-		s = of_prop_next_string(prop, s))
 
 #else /* CONFIG_OF */
 
@@ -505,12 +494,20 @@ static inline int of_machine_is_compatible(const char *compat)
 	return 0;
 }
 
+static inline const __be32 *of_prop_next_u32(struct property *prop,
+		const __be32 *cur, u32 *pu)
+{
+	return NULL;
+}
+
+static inline const char *of_prop_next_string(struct property *prop,
+		const char *cur)
+{
+	return NULL;
+}
+
 #define of_match_ptr(_ptr)	NULL
 #define of_match_node(_matches, _node)	NULL
-#define of_property_for_each_u32(np, propname, prop, p, u) \
-	while (0)
-#define of_property_for_each_string(np, propname, prop, s) \
-	while (0)
 #endif /* CONFIG_OF */
 
 #ifndef of_node_to_nid
@@ -559,6 +556,18 @@ static inline int of_property_read_u32(const struct device_node *np,
 	return of_property_read_u32_array(np, propname, out_value, 1);
 }
 
+#define of_property_for_each_u32(np, propname, prop, p, u)	\
+	for (prop = of_find_property(np, propname, NULL),	\
+		p = of_prop_next_u32(prop, NULL, &u);		\
+		p;						\
+		p = of_prop_next_u32(prop, p, &u))
+
+#define of_property_for_each_string(np, propname, prop, s)	\
+	for (prop = of_find_property(np, propname, NULL),	\
+		s = of_prop_next_string(prop, NULL);		\
+		s;						\
+		s = of_prop_next_string(prop, s))
+
 #if defined(CONFIG_PROC_FS) && defined(CONFIG_PROC_DEVICETREE)
 extern void proc_device_tree_add_node(struct device_node *, struct proc_dir_entry *);
 extern void proc_device_tree_add_prop(struct proc_dir_entry *pde, struct property *prop);