of: constify of_property_check_flags() prop argument

This argument is not modified and thus can be set as const.
Signed-off-by: Clément Léger <clement.leger@bootlin.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220601081801.348571-2-clement.leger@bootlin.com

include/linux/of.h

@@ -207,7 +207,7 @@ static inline void of_node_clear_flag(struct device_node *n, unsigned long flag)
 }
 
 #if defined(CONFIG_OF_DYNAMIC) || defined(CONFIG_SPARC)
-static inline int of_property_check_flag(struct property *p, unsigned long flag)
+static inline int of_property_check_flag(const struct property *p, unsigned long flag)
 {
 	return test_bit(flag, &p->_flags);
 }
@@ -814,7 +814,8 @@ static inline void of_node_clear_flag(struct device_node *n, unsigned long flag)
 {
 }
 
-static inline int of_property_check_flag(struct property *p, unsigned long flag)
+static inline int of_property_check_flag(const struct property *p,
+					 unsigned long flag)
 {
 	return 0;
 }