[Income of permanent land funds of New Mexico highlands

university pledged.] That from and after the passage and approval of this act [21-3-13, 21-3-14, 21-3-16 to 21-3-28 NMSA 1978], all permanent funds thereafter derived from the sale or disposition of the lands held in trust for New Mexico normal university [New Mexico highlands university] shall be invested in the same manner as other permanent funds of the state of New Mexico are authorized to be invested, the income from which shall likewise form a part of the pledged income for the payment of principal and interest of bonds issued by the board of regents of the New Mexico normal university [New Mexico highlands university] under the provisions of this act.