[PATCH 5/8] ARM: PXA: Z2: Add poweroff function

[Eric Miao]

>> No need, I understand how it works, PSPR is null, so after u-boot loads
>> PSPR to pc it performs 'soft reset' (jumps to 0x0, to begin of NOR flash),
>> RCSR bits are already cleared, so it just boots kernel.
>
> The note in Table 18 -- Exit from sleep or deep-sleep doesn't clear or set this
> bit -- means PSPR might not be null if you use your deep-sleep-parapowerdown.

PSPR is preserved during sleep/deep-sleep. Yet the actual implemention
of deep-sleep depends on the boot-loader.

The resume process is basically same as software reboot, and the BootROM
is supposed to load the bootloader instead of resuming from PSPR since the
RAM content is not preserved.