45-7. Agent to sell under power may be appointed by parol.
All sales of real property, under a power of sale contained in any mortgage or deed of trust to secure the payment of money, by any mortgagee or trustee, through an agent or attorney for that purpose, appointed orally or in writing by such mortgagee or trustee, whether such writing has been or shall be registered or not, shall be valid, whether or not such mortgagee or trustee was or shall be present at such sale.