GPIO : support ascend_gpio_dwapb_enable switch

ascend inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4JMQA



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Hi everyone,
This patch register a setup function for ascend gpio driver.
With this patch, we can enable ascend gpio function independently,
so that we can turn this feature on or off through bootargs.

Signed-off-by: zhangguijiang <zhangguijiang@huawei.com>
Reviewed-by: Ding Tianhong <dingtianhong@huawei.com>
Reviewed-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>