The original patch was to add compatible string for Hi3519 soc
and do some cleanup.

Since the generic machine entry could meet most of the cases,
so I did a further cleanup to reuse it and just keep one machine
entry that needs map_io here.
Signed-off-by: Jiancheng Xue <xuejiancheng@huawei.com>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>