net: hns: use platform_get_irq instead of irq_of_parse_and_map

As irq_of_parse_and_map is only used by DT case, it is excepted to use
a uniform interface. So it is used platform_get_irq() instead.

Signed-off-by: Kejian Yan <yankejian@huawei.com>
Signed-off-by: Yisen Zhuang <Yisen.Zhuang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>