71-1-208. Recording of subordination or waiver agreements. A subordination agreement or a waiver in favor of subsequent purchasers, encumbrancers, or mortgagees as regards any real estate mortgage of record or the property therein included may be recorded in like manner as a real estate mortgage, and such record shall operate as due and legal notice to the mortgagor and the mortgagee and to all other interested persons. Any such subordination agreement or waiver shall be valid and binding so far as the mortgage therein referred to or the property covered by such mortgage is concerned, when executed by the record holder of the mortgage involved.