sw64: do not include sw64io.h in io.h

Sunway inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I56OLG



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We consider io.h as a basic header which should be decoupled with
platforms and chipsets, so it's better to remove sw64io.h from
io.h, and do something necessary to make it build ok.

Signed-off-by: He Sheng <hesheng@wxiat.com>

Signed-off-by: Gu Zitao <guzitao@wxiat.com>