Bug#484693: Bug affects *all* powerpc archs
This problem (and it's fix) is *not* PPC64 specific. The exact same
problems occur on 32 bit powerpc platforms, and remain unaddressed.
Accordingy, I've reopened this bug.
I've rebuilt the powerpc configured kernel with CONFIG_RTC_DRV_PPC=m. I
added it to the initramfs, and loaded it at boot. This resolved the
issues with setting the hwclock.
Please apply CONFIG_RTC_DRV_PPC to all powerpc configurations.