hw/ppc/vof: Do not include the full "cpu.h"

"vof.h" doesn't need the full "cpu.h" to get the target_ulong
definition, including "exec/cpu-defs.h" is enough.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20221213123550.39302-3-philmd@linaro.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

include/hw/ppc/vof.h

@@ -9,7 +9,7 @@
 #include "qom/object.h"
 #include "exec/address-spaces.h"
 #include "exec/memory.h"
-#include "cpu.h"
+#include "exec/cpu-defs.h"
 
 typedef struct Vof {
     uint64_t top_addr; /* copied from rma_size */