Quick Tip – The PowerShell code below adds it as a Site Column, once you do that navigate to your custom Content Type and add it from existing site columns.
Add-PSSnapin Microsoft.SharePoint.Powershell -ErrorAction SilentlyContinue
$fieldXml = “<Field Type=’Geolocation’ DisplayName=’My Location’ />”
$web = Get-SPWeb $webUrl
$fieldName = $web.Fields.AddFieldAsXml($fieldXml)
$web.Update()
Cheers,
Oscar