net/hns3: fix supported speed of copper ports

net/hns3: fix supported speed of copper ports

The "supported capability" obtained from firmware on copper ports
includes the speed capability, auto-negotiation capability, and flow
control capability. Therefore, this patch changes "supported_capa" to
"supported_speed" and parses the speed capability supported by the
driver from the "supported capability".

Fixes: 2e4859f3b362 ("net/hns3: support PF device with copper PHYs")

Signed-off-by: Huisong Li <lihuisong@huawei.com>
Signed-off-by: Min Hu (Connor) <humin29@huawei.com>