I suggest that instead of this fix (that is ommiting the 5G case btw), we rewrite
the whole ctrl assignment as :

	switch (speed) {
	case SPEED_100000:
		ctrl |= priv->hw->link.xlgmii.speed100000;
		break;
	case SPEED_50000:
		ctrl |= priv->hw->link.xlgmii.speed50000;
		break;
	case SPEED_40000:
		ctrl |= priv->hw->link.xlgmii.speed40000;
		break;
	case SPEED_25000:
		ctrl |= priv->hw->link.xlgmii.speed25000;
		break;
	case SPEED_10000:
		ctrl |= priv->hw->link.xgmii.speed10000;
		break;
	case SPEED_5000:
		ctrl |= priv->hw->link.xgmii.speed5000;
		break;
	case SPEED_2500:
		if (interface == PHY_INTERFACE_MODE_USXGMII)
			ctrl |= priv->hw->link.xgmii.speed2500;
		else
			ctrl |= priv->hw->link.speed2500;
		break;
	case SPEED_1000:
		ctrl |= priv->hw->link.speed1000;
	case SPEED_100:
		ctrl |= priv->hw->link.speed100;
		break;
	case SPEED_10:
		ctrl |= priv->hw->link.speed10;
		break;
	default:
		return;
	}

The bug description makes it sound like it was not obvious to
debug. So maybe put an error message in the default: to aid the next
developer who hits it with SPEED_14000, or whatever comes next.

	  Andrew