pci: Rename PCI_REGION_MEMORY to PCI_REGION_SYS_MEMORY for clarity

The PCI_REGION_MEMORY and PCI_REGION_MEM are a bit to similar and
can be confusing when reading the code.

Rename PCI_REGION_MEMORY to PCI_REGION_SYS_MEMORY to clarify its used
for system memory mapping purposes.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/drivers/pci/pci_ixp.c b/drivers/pci/pci_ixp.c
index aae3d3d..3b303b4 100644
--- a/drivers/pci/pci_ixp.c
+++ b/drivers/pci/pci_ixp.c
@@ -240,7 +240,7 @@
 	/* System memory space */
 	pci_set_region (hose->regions + 0,
 			PCI_MEMORY_BUS,
-			PCI_MEMORY_PHY, PCI_MEMORY_SIZE, PCI_REGION_MEMORY);
+			PCI_MEMORY_PHY, PCI_MEMORY_SIZE, PCI_REGION_SYS_MEMORY);
 
 	/* PCI memory space */
 	pci_set_region (hose->regions + 1,