powerpc/powernv: Double size of log blob

Each PHB instance (struct pnv_phb) has its corresponding log blob,
which is used to hold the retrieved error log from firmware. The
current size of that (4096) isn't enough for PHB3 case and the patch
makes that double to 8192.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/powernv/pci.h

@@ -17,7 +17,7 @@ enum pnv_phb_model {
 	PNV_PHB_MODEL_PHB3,
 };
 
-#define PNV_PCI_DIAG_BUF_SIZE	4096
+#define PNV_PCI_DIAG_BUF_SIZE	8192
 #define PNV_IODA_PE_DEV		(1 << 0)	/* PE has single PCI device	*/
 #define PNV_IODA_PE_BUS		(1 << 1)	/* PE has primary PCI bus	*/
 #define PNV_IODA_PE_BUS_ALL	(1 << 2)	/* PE has subordinate buses	*/