I use the same plugin on my site, it was a bit of a nightmare to get going, but in the end the way i got it to work was to have each of the fileupload modules as its own path in my requirejs.config (in my main.js), like so:
...
'jquery.ui.widget': '../Scripts/fileupload/js/vendor/jquery.ui.widget',
'jquery_iframe_transport': '../Scripts/fileupload/js/jquery.iframe-transport',
'jquery.fileupload': '../Scripts/fileupload/js/jquery.fileupload',
'jquery.fileupload-image': '../Scripts/fileupload/js/jquery.fileupload-image',
'jquery.fileupload-audio': '../Scripts/fileupload/js/jquery.fileupload-audio',
'jquery.fileupload-video': '../Scripts/fileupload/js/jquery.fileupload-video',
'jquery.fileupload-validate': '../Scripts/fileupload/js/jquery.fileupload-validate',
'jquery.fileupload-process': '../Scripts/fileupload/js/jquery.fileupload-process',
'jquery.fileupload-fp': '../Scripts/fileupload/js/jquery.fileupload-fp',
'jquery.fileupload-ui': '../Scripts/fileupload/js/jquery.fileupload-ui',
...
i could then require it with: 'jquery.fileupload'