net: ngbevf: add link update flow

Add link update flow to wangxun 1G virtual functions.
Get link status from pf in mbox, and if it is failed then
check the vx_status, because vx_status switching is too slow.

Signed-off-by: Mengyuan Lou <mengyuanlou@net-swift.com>
Link: https://patch.msgid.link/20250704094923.652-13-mengyuanlou@net-swift.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>