Drupal 7: entity field as single/multivalued based on content type
Shortly, no.  

Take a look at project Field instance cardinality and an issue #1029298.  


  This currently only works with fields that use options widgets (ie select list or checkboxes), and only allows them to be overridden to be single-valued.


Theoretically, you can create field as multi-valued and limit cardinality for content type X programmatically.