[pymtl] added auto clock toggling for VCD output
[pymtl] added auto clock toggling for VCD output

Abhinav117/pymtl,Abhinav117/pymtl,Glyfina-Fernando/pymtl,tj93/pymtl,Abhinav117/pymtl,jck/pymtl,tj93/pymtl,cornell-brg/pymtl,jjffryan/pymtl,cfelton/pymtl,12yujim/pymtl,tj93/pymtl,cornell-brg/pymtl,jck/pymtl,12yujim/pymtl,Glyfina-Fernando/pymtl,cornell-brg/pymtl,Glyfina-Fernando/pymtl,jjffryan/pymtl,jjffryan/pymtl,cfelton/pymtl,cfelton/pymtl,12yujim/pymtl,Abhinav117/pymtl,jck/pymtl