ppc4xx: Fix spelling error in MAINTAINERS file

Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/MAINTAINERS b/MAINTAINERS
index 260c3e6..a7f9b87 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -319,8 +319,8 @@
 
 	ml507 		PPC440x5
 	v5fx30teval	PPC440x5
-	xilinx-pp440-generic	PPC440x5
-	xilinx-pp405-generic	PPC405
+	xilinx-ppc405-generic	PPC405
+	xilinx-ppc440-generic	PPC440x5
 
 Stefan Roese <sr@denx.de>