machine.c doesn't use any target-specific macro defined by
the "migration/cpu.h" header. Use the minimum header required:
"migration/qemu-file-types.h" and "migration/vmstate.h", which
are not target-specific.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 target/alpha/machine.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/target/alpha/machine.c b/target/alpha/machine.c
index 6828b123ca1..dcba5d441be 100644
--- a/target/alpha/machine.c
+++ b/target/alpha/machine.c
@@ -1,6 +1,7 @@
 #include "qemu/osdep.h"
 #include "cpu.h"
-#include "migration/cpu.h"
+#include "migration/qemu-file-types.h"
+#include "migration/vmstate.h"
 
 static int get_fpcr(QEMUFile *f, void *opaque, size_t size,
                     const VMStateField *field)
-- 
2.52.0