Add Coherent Sensors to Smartoptics DCP2

I have code to add sensors to read/graph the values for coherent pluggable optics in the Smartoptics DCP2. Has been tested with DCP-404 and DCP-1203 line cards.

The correct MIB file is already part of Observium. These entries need to be added to the smartoptics.inc.php file.

Note- I've only included the additions to the file.