[PPC440SPe] Improve PCIe configuration space access

- correct configuration space mapping
- correct bus numbering
- better access to config space

Prior to this patch, the 440SPe host/PCIe bridge was able to configure only the
first device on the first bus. We now allow to configure up to 16 buses;
also, scanning for devices behind the PCIe-PCIe bridge is supported, so
peripheral devices farther in hierarchy can be identified.

Signed-off-by: Grzegorz Bernacki <gjb@semihalf.com>
diff --git a/include/configs/katmai.h b/include/configs/katmai.h
index b6d0f51..7834e39 100644
--- a/include/configs/katmai.h
+++ b/include/configs/katmai.h
@@ -66,11 +66,11 @@
 #define CFG_PCIE_BASE		0xe0000000	/* PCIe UTL regs */
 
 #define CFG_PCIE0_CFGBASE	0xc0000000
-#define CFG_PCIE0_XCFGBASE	0xc0000400
-#define CFG_PCIE1_CFGBASE	0xc0001000
-#define CFG_PCIE1_XCFGBASE	0xc0001400
-#define CFG_PCIE2_CFGBASE	0xc0002000
-#define CFG_PCIE2_XCFGBASE	0xc0002400
+#define CFG_PCIE1_CFGBASE	0xc1000000
+#define CFG_PCIE2_CFGBASE	0xc2000000
+#define CFG_PCIE0_XCFGBASE	0xc3000000
+#define CFG_PCIE1_XCFGBASE	0xc3001000
+#define CFG_PCIE2_XCFGBASE	0xc3002000
 
 /* System RAM mapped to PCI space */
 #define CONFIG_PCI_SYS_MEM_BUS	CFG_SDRAM_BASE