attribute_groups are not supposed to change at runtime. All functions
working with attribute_groups provided by <linux/device.h> work with const
attribute_group. So mark the non-const structs as const.
File size before:
text data bss dec hex filename
995 608 0 1603 643 sound/pci/hda/hda_sysfs.o
File size After adding 'const':
text data bss dec hex filename
1035 544 0 1579 62b sound/pci/hda/hda_sysfs.o