powerpc/powernv: Debugfs directory for PHB

The patch creates one debugfs directory ("powerpc/PCIxxxx") for
each PHB so that we can hook EEH error injection debugfs entry
there in proceeding patch.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
index 3656a240..43906e3 100644
--- a/arch/powerpc/platforms/powernv/pci.h
+++ b/arch/powerpc/platforms/powernv/pci.h
@@ -96,6 +96,10 @@
 	int			removed;
 #endif
 
+#ifdef CONFIG_DEBUG_FS
+	struct dentry		*dbgfs;
+#endif
+
 #ifdef CONFIG_PCI_MSI
 	unsigned int		msi_base;
 	unsigned int		msi32_support;