powerpc: Remove <common.h> and add needed includes

Remove <common.h> from all powerpc architecture files and when needed add
missing include files directly. This typically involves using
<asm/u-boot.h> instead due to the difficult nested structure of the
PowerPC includes themselves.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/powerpc/lib/bootm.c b/arch/powerpc/lib/bootm.c
index 75c6bfd..f55b5ff 100644
--- a/arch/powerpc/lib/bootm.c
+++ b/arch/powerpc/lib/bootm.c
@@ -7,7 +7,7 @@
  */
 
 
-#include <common.h>
+#include <config.h>
 #include <bootm.h>
 #include <bootstage.h>
 #include <cpu_func.h>