sif: Add a feature mask to allow internal vlink state to follow ext.links

sif: Add a feature mask to allow internal vlink state to follow ext.links

SIF implements an internal IB switch for each port - all HCA vPorts are
connected to this switch, which again has a single external port
associated with the actual state of the physical port.

Some of the current management software assumes that a failed external port
of an HCA can be observed by looking at the local port, which is not
the case with SIF, where the local virtual port will not go down
if the external link goes down.

Firmware implements a mode to logically "wire" the vPort to the
corresponding physical port to mimic the legacy behaviour.

This mode can be enabled by OR'ing in 0x10000 in the module parameter
feature_mask. This is a temporary fix until management software can handle
this topology better.

Orabug: 23509653

Signed-off-by: Knut Omang <knut.omang@oracle.com>