powerpc/powernv: Remove misleading comment in pci.c

PCI in powernv now supports quite a bit more than p5ioc2, so remove the
outdated comment.
Signed-off-by: Russell Currey <ruscur@russell.cc>
Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/powernv/pci.c

 /*
  * Support PCI/PCIe on PowerNV platforms
  *
- * Currently supports only P5IOC2
- *
  * Copyright 2011 Benjamin Herrenschmidt, IBM Corp.
  *
  * This program is free software; you can redistribute it and/or