These are not addresses but the configuration of the PIN. You can download the iMX8MP Hardware Reference from NXP’s website for free, and that has all documentation to reference what setting these bits does for a specific pin mux configuration.
To change a pin, you need to use the GPIO mux definition for that pin. For example MX8MP_IOMUXC_ECSPI2_MISO__ECSPI2_MISO would be MX8MP_IOMUXC_ECSPI2_MISO__GPIO5_IO12 and then you need to configure that pin according to the reference manual, setting bits for pull up / down drive strength, hysteresis, open drain, etc.
Just remember you need to remove the old definition when you create a new pin definition or else there will be a collision in definitions.