net: hns3: split function hns3_handle_bdinfo()

Function hns3_handle_bdinfo() is a bit too long. So add two
new functions hns3_handle_rx_ts_info() and hns3_handle_rx_vlan_tag(
to simplify code and improve code readability.

Signed-off-by: Yufeng Mo <moyufeng@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>