update vdmos examples to the new model interface

examples/vdmos/self-heating.sp

@@ -0,0 +1,24 @@
+VDMOS self heating test
+M1 D G 0 t tc IRFP240 tnodeout
+rthk tc 0 0.05
+VG G 0 5V Pulse 0 10 0 1m 1m 100m 200m
+*RD D D1 4
+VD D 0 2V
+.model IRFP240 VDMOS nchan
++ Vto=4 Kp=5.9 Lambda=.001 Theta=0.015 ksubthres=.27
++ Rd=61m Rs=18m Rg=3 Rds=1e7
++ Cgdmax=2.45n Cgdmin=10p a=0.3 Cgs=1.2n
++ Is=60p N=1.1 Rb=14m XTI=3
++ Cjo=1.5n Vj=0.8 m=0.5
++ tcvth=0.0065 MU=-1.27 texp0=1.5
++ Rthjc=0.02 Cthj=1e-3 Rthca=100
++ mtriode=0.8
+.control
+dc vd 0.1 50 .1 vg 5 13 2
+plot -i(vd)
+settype temperature v(t) v(tc)
+plot v(t) v(tc)
+*tran 1m 0.01
+*plot v(d) v(g)
+.endc
+.end