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/cpu/mpc85xx/traps.c b/arch/powerpc/cpu/mpc85xx/traps.c
index 8f451b4..db70f07 100644
--- a/arch/powerpc/cpu/mpc85xx/traps.c
+++ b/arch/powerpc/cpu/mpc85xx/traps.c
@@ -19,7 +19,7 @@
  * This file handles the architecture-dependent parts of hardware exceptions
  */
 
-#include <common.h>
+#include <asm/ppc.h>
 #include <asm/global_data.h>
 #include <asm/ptrace.h>
 #include <command.h>