net: hns3: use string choices helper

Use string choices helper for better readability.

Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250307113733.819448-1-shaojijie@huawei.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>