powerpc/pci: Fix comments about ppc_md.pcibios_fixup

The patch fixes the comments about ppc_md.pcibios_fixup(), which
should be called after allocating resources.

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

arch/powerpc/include/asm/machdep.h

@@ -125,7 +125,7 @@ struct machdep_calls {
 	unsigned int	(*get_irq)(void);
 
 	/* PCI stuff */
-	/* Called after scanning the bus, before allocating resources */
+	/* Called after allocating resources */
 	void		(*pcibios_fixup)(void);
 	int		(*pci_probe_mode)(struct pci_bus *);
 	void		(*pci_irq_fixup)(struct pci_dev *dev);