ice: check if SF is ready in ethtool ops

Now there is another type of port representor. Correct checking if
parent device is ready to reflect also new PR type.

Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>