add automatically generated EWSB eqs. solution to the SMSSM model file

The solution was generated like this:

 1. Omitting TreeLevelEWSBSolution from the model file

 2. Run FlexibleSUSY

 3. FlexibleSUSY cannot reduce the multiple solutions of the EWSB
    eqs. but prints the analytic solution to a file.

 4. From this file the solution was manually reduced by introducing
    Sign[Mu] at the right place.  This solution was then copied
    into the model file.