HID: introduce proper dependency of HID_BATTERY on POWER_SUPPLY
ppc6xx_defconfig reveals this:
drivers/built-in.o: In function `hidinput_cleanup_battery': drivers/hid/hid-input.c:351: undefined reference to`power_supply_unregister'
drivers/built-in.o: In function `hidinput_setup_battery': drivers/hid/hid-input.c:338: undefined reference to `power_supply_register'
make[1]: *** [.tmp_vmlinux1] Error 1
The defconfig in question doens't mention either option and kbuild is
genertaing