bnxt_en: Restrict a PF in Multi-Host mode from changing port PHY configuration

This change restricts the PF in multi-host mode from setting any port
level PHY configuration.  The settings are controlled by firmware in
Multi-Host mode.

Signed-off-by: Deepak Khungar <deepak.khungar@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>