[SalesForce] How to add placeholder for lightning:InputField

Looks like the value attribute is added now as a part of lightning:inputfield. To create a record here is a below code thats working for me

<aura:component implements="force:hasRecordId,flexipage:availableForRecordHome">

<aura:attribute name="companyName" type="String"/>
   <lightning:layout verticalAlign="start" multipleRows="true">
    <lightning:layoutItem flexibility="auto" padding="around-small">
        <lightning:input type="text" label="Campaign" value="{!v.companyName}" aura:id="cmpName" onchange="{!c.handleOnchange}"/>
        <lightning:recordEditForm aura:id="recordEditForm" 
                            objectApiName="Lead" onsuccess="{!c.handleSuccess}" onsubmit="{!c.handleSubmit}" onload="{!c.handleOnload}">
            <lightning:messages />
            <lightning:inputField fieldName="Name" />
            <lightning:inputField fieldName="Company" value="{!v.companyName}" aura:id="company"/>
            <lightning:inputField fieldName="Phone" />
            <lightning:button  variant="brand" class="btn" type="submit" label="Create new lead" />
        </lightning:recordEditForm>
    </lightning:layoutItem>
   </lightning:layout>
</aura:component>

The Controller code for same

({
    handleSuccess : function(component, event, helper) {
      console.log(event.getParams().response);
      for (let key of Object.keys(event.getParams().response)) {
        console.log(key + event.getParams().response[key]);
      }
     console.log(event.getParams().response.id);
},

handleOnchange : function(component, event, helper) {
    component.find("company").set("v.fieldName","Company");
    var company = component.get("v.companyName")
    component.find("company").set("v.value",company);
},

  handleOnload : function(component, event, helper) {
    console.log('Load Event' + JSON.stringify(event.getParams()));
  },
})

I found a workaround. I just put the onchange event on the parent div as shown below. However, it would be nice to be able to assign it directly to lightning:inputField. I assume there is a bug in the code.

var changeOrderType = component.getReference("c.changeOrderType");
    newComponents.push(["aura:html", {"tag": "div", "HTMLAttributes": {"class": "slds-form-element__control", "onchange": changeOrderType}}]);      
    newComponents.push(["lightning:inputField", {"fieldName"  : "Contract_type__c", "aura:id": "input_contract_type__c", "value": contract.Contract_type__c}]);