Add calvingCFLdt to restarts

This is needed for the calving CFL to behave correctly on a restart.
This variable is only needed in a restart file if the calving CFL is
actually being applied, but including it always because it is only a
scalar value, and adding logic for that would be complicated.

components/mpas-albany-landice/src/Registry.xml

@@ -799,6 +799,8 @@
                         <var name="floatingVonMisesThresholdStress"/>
                         <var name="stiffnessFactor"/>
                         <var name="calvingMask"/>
+                        <!-- calvingCFLdt only needed if calving CFL is being applied, but it is a scalar value so no harm in including it always -->
+                        <var name="calvingCFLdt"/> 
                         <var name="upliftRate"/>
 			<!-- normalVelocity is needed for advection on the next timestep -->
 			<var name="normalVelocity"/>