vhost-vdpa: Remove redundant declaration of address_space_memory

The symbol address_space_memory are already declared in
include/exec/address-spaces.h. So let's add this header file
and remove the redundant declaration in include/hw/virtio/vhost-vdpa.h.

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20210517123246.999-1-xieyongji@bytedance.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

hw/virtio/vhost-vdpa.c

@@ -18,6 +18,7 @@
 #include "hw/virtio/vhost-backend.h"
 #include "hw/virtio/virtio-net.h"
 #include "hw/virtio/vhost-vdpa.h"
+#include "exec/address-spaces.h"
 #include "qemu/main-loop.h"
 #include "cpu.h"
 #include "trace.h"

include/hw/virtio/vhost-vdpa.h

@@ -21,5 +21,4 @@ typedef struct vhost_vdpa {
     struct vhost_dev *dev;
 } VhostVDPA;
 
-extern AddressSpace address_space_memory;
 #endif