Support for the OMD-EM5 11 was introduced with the Adobe Camera Raw Plugin version 8.8 for Photoshop CS6 and CC. There has been no corresponding update to LR 5.8, the latest version is 5.7.1.
See the link below which provides additional info.
Quote "Lightroom Customers –
If you’re using one of the newly supported cameras listed above, please download the DNG Converter. We’re working to add support to these cameras and they will be added in the next Lightroom release."
How do I get Adobe Lightroom 5 to work with my Olympus OMD-EM 5 II camera?
There are significant indicators that you may have what you want tomorrow.