rpi3: Implement PSCI_SYSTEM_OFF

This implementation doesn't actually turn the system off, it simply
reboots it and prevents it from booting while keeping it in a low power
mode.

Change-Id: I7f72c9f43f25ba0341db052bc2be4774c88a7ea3
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
2 files changed