The patch adds I/O chip backend to retrieve the state for the
indicated PE. While the PE state is temperarily unavailable,
the upper layer (powernv platform) should return default delay
(1 second).
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>