relax CddInterface header inclusion of "setoper.h"

[kamalsaleh]

resolves #45

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.43%. Comparing base (d43b3e2) to head (395ca9d).
Report is 2 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master      #46   +/-   ##
=======================================
  Coverage   89.43%   89.43%           
=======================================
  Files           5        5           
  Lines         899      899           
  Branches       30       30           
=======================================
  Hits          804      804           
  Misses         91       91           
  Partials        4        4           

Files with missing lines	Coverage Δ
src/CddInterface.c	94.55% <ø> (ø)