bnxt_en: Send PF driver unload notification to all VFs.

bnxt_en: Send PF driver unload notification to all VFs.

Orabug: 23221795

During remove_one() when SRIOV is enabled, the PF driver
should broadcast PF driver unload notification to all
VFs that are attached to VMs. Upon receiving the PF
driver unload notification, the VF driver should print
a warning message to message log.  Certain operations on the
VF may not succeed after the PF has unloaded.

Signed-off-by: Jeffrey Huang <huangjw@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 19241368443ff976b1924019d29eef8e972158e7)
Signed-off-by: Brian Maly <brian.maly@oracle.com>