net: hns3: split function hclge_init_vlan_config()

Currently the function hclge_init_vlan_config() is a bit long.
Split it to several small functions, to simplify code and
improve code readability.

Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>