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/board/esd/common/pci.c b/board/esd/common/pci.c
index dcb764c..83f8103 100644
--- a/board/esd/common/pci.c
+++ b/board/esd/common/pci.c
@@ -179,7 +179,7 @@
   /* System memory space */
   pci_set_region(hose->regions + 0,
 		 0x00000000, 0x00000000, 0x01000000,
-		 PCI_REGION_MEM | PCI_REGION_MEMORY);
+		 PCI_REGION_MEM | PCI_REGION_SYS_MEMORY);
 
   /* PCI Memory space */
   pci_set_region(hose->regions + 1,