ppc: Move lbc_clk and cpu to arch_global_data

Move these fields into arch_global_data and tidy up.

Signed-off-by: Simon Glass <sjg@chromium.org>
[trini: Update for bsc9132qds.c, b4860qds.c]
Signed-off-by: Tom Rini <trini@ti.com>
diff --git a/board/freescale/bsc9131rdb/bsc9131rdb.c b/board/freescale/bsc9131rdb/bsc9131rdb.c
index 2e0e55f..fe870b6 100644
--- a/board/freescale/bsc9131rdb/bsc9131rdb.c
+++ b/board/freescale/bsc9131rdb/bsc9131rdb.c
@@ -59,7 +59,7 @@
 {
 	struct cpu_type *cpu;
 
-	cpu = gd->cpu;
+	cpu = gd->arch.cpu;
 	printf("Board: %sRDB\n", cpu->name);
 
 	return 0;