net/bnxt: fix unnecessary delay in port stop

net/bnxt: fix unnecessary delay in port stop

VFs and multifunction PFs do not have the privilege to change
link configuration. We force the physical link down as a part
of device stop only for single physical function(SPF).

This change also helps in eliminating the logs when a VF port
is stopped:

"Port 0: link state change event"
"bnxt_print_link_info(): Port 0 Link Up - speed 25000 Mbps - full-duplex"

Fixes: 316e412299fd ("net/bnxt: fix crash when closing")
Cc: stable@dpdk.org
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>