We need to add include/sysemu/block-backend-io.h to the inputs of the
block-gen.c target defined in block/meson.build.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220705161527.1054072-7-afaria@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>