ppc4xx: Complete PMC440 board support

This patch brings the PMC440 board configuration file.
Finally it enables the PMC440 board support.

Signed-off-by: Matthias Fuchs <matthias.fuchs@esd-electronics.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index be0b8d3..fa0e9ea 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -158,6 +158,7 @@
 	PCI405			PPC405GP
 	PLU405			PPC405EP
 	PMC405			PPC405GP
+	PMC440			PPC440EPx
 	VOH405			PPC405EP
 	VOM405			PPC405EP
 	WUH405			PPC405EP