Lite5200 shouldn't mess with ROOT_DEV

There is no good reason for board platform code to mess with the ROOT_DEV.
Remove it from all in-tree platforms except powermac

This is a follow on to commit 745e1027.
The original patch had this change to lite5200.c, but it got dropped in
the psycho madness that is the 2.6.24 merge window.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/powerpc/platforms/52xx/lite5200.c

@@ -158,18 +158,6 @@ static void __init lite5200_setup_arch(void)
 		of_node_put(np);
 	}
 #endif
-
-#ifdef CONFIG_BLK_DEV_INITRD
-	if (initrd_start)
-		ROOT_DEV = Root_RAM0;
-	else
-#endif
-#ifdef  CONFIG_ROOT_NFS
-		ROOT_DEV = Root_NFS;
-#else
-		ROOT_DEV = Root_HDA1;
-#endif
-
 }
 
 /*