net/ncsi: Don't enable all channels when HWA available

NCSI hardware arbitration allows multiple packages to be enabled at once
and share the same wiring. If the NCSI driver recognises that HWA is
available it unconditionally enables all packages and channels; but that
is a configuration decision rather than something required by HWA.
Additionally the current implementation will not failover on link events
which can cause connectivity to be lost unless the interface is manually
bounced.

Retain basic HWA support but remove the separate configuration path to
enable all channels, leaving this to be handled by a later
implementation.

Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>