sysfs: transparently handle const pointers in ATTRIBUTE_GROUPS()

To ease the constification process of 'struct attribute', transparently
handle the const pointers in ATTRIBUTE_GROUPS(). A cast is used instead
of assigning to .attrs_new as it keeps the macro smaller. As both
members are aliased to each other the result is identical.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20251029-sysfs-const-attr-prep-v5-2-ea7d745acff4@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/sysfs.h

@@ -287,7 +287,12 @@ static const struct attribute_group *_name##_groups[] = {	\
 
 #define ATTRIBUTE_GROUPS(_name)					\
 static const struct attribute_group _name##_group = {		\
-	.attrs = _name##_attrs,					\
+	.attrs = _Generic(_name##_attrs,			\
+			  struct attribute **:			\
+				_name##_attrs,			\
+			  const struct attribute *const *:	\
+				(void *)_name##_attrs		\
+	),							\
 };								\
 __ATTRIBUTE_GROUPS(_name)