Document localMatrix parameter in setSparsityPattern

Added parameter documentation for localMatrix in setSparsityPattern.

src/coreComponents/physicsSolvers/PhysicsSolverBase.hpp

@@ -406,6 +406,7 @@ class PhysicsSolverBase : public ExecutableGroup
    * @brief Set the sparsity pattern of the linear system matrix
    * @param domain the domain containing the mesh and fields
    * @param dofManager degree-of-freedom manager associated with the linear system
+   * @param localMatrix the system matrix
    * @param pattern the sparsity pattern to be filled
    */
   virtual void