ppc4xx: Consolidate some of the 405 and 440 macros/structs into 4xx

This patch moves some common 4xx macros and the PPC405_SYS_INFO/
PPC440_SYS_INFO structure into the common ppc4xx.h header.

Lot's of other macros are good candidates to be consolidated this way
in the future.

Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/board/mpl/common/common_util.c b/board/mpl/common/common_util.c
index f3aa0a7..8d4cbe8 100644
--- a/board/mpl/common/common_util.c
+++ b/board/mpl/common/common_util.c
@@ -587,7 +587,7 @@
 void video_get_info_str (int line_number, char *info)
 {
 	/* init video info strings for graphic console */
-	PPC405_SYS_INFO sys_info;
+	PPC4xx_SYS_INFO sys_info;
 	char rev;
 	int i,boot;
 	unsigned long pvr;