It appears the "reset instead of halt" feature is controlled via a config menu that isn't used for all architectures. Hence it is not available on ppc64/arm.
The "reset instead of halt" feature is configured via kernel/power/Kconfig. However, this file is only sourced by ia64/ppc/i386/frv/x86_64. Any architectures other than those (included ppc64 and arm) will not be able to select CONFIG_ALWAYS_RESTART. IDENTIFIER = WIND00119585