ppc4xx: Rename CONFIG_XILINX_ML300 to CONFIG_XILINX_405

This change helps with better handling with others
Xilinx based platform.

Signed-off-by: Michal Simek <monstr@monstr.eu>
Acked-by: Stefan Roese <sr@denx.de>
diff --git a/lib_ppc/board.c b/lib_ppc/board.c
index 96c573c..9afa88a 100644
--- a/lib_ppc/board.c
+++ b/lib_ppc/board.c
@@ -625,7 +625,7 @@
     defined(CONFIG_440EPX) || defined(CONFIG_440GRX)
 	bd->bi_pci_busfreq = get_PCI_freq ();
 	bd->bi_opbfreq = get_OPB_freq ();
-#elif defined(CONFIG_XILINX_ML300)
+#elif defined(CONFIG_XILINX_405)
 	bd->bi_pci_busfreq = get_PCI_freq ();
 #endif
 #endif