How to configure DT to recognize external SPI UART IRQ?

Hi, I have a need to hook up an external MAX3108 to SPI1 on the Radxa-Zero 40-pin header. I do not know how to tell the system which GPIO pin on the 40-pin header should be used as IRQ line.

I found the device tree binding file for the MAX3108 so I have an idea of what additions are needed for the MAX3108 but I don’t know how to deal with the interrupt routing in the device tree file. I’d appreciate some pointers.