powerpc/powernv: Allow to freeze PE

The patch synchronizes header file with firmware to have new OPAL
API opal_pci_eeh_freeze_set(), which is used to freeze the specified
PE in order to support "compound" PE.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>