How to set 80MHZ frequency of SPI4 of STM32h745Kii

Hello

I am working on stm32h745 controller, I am configuring the DAC SPI . For the DAC minimum frequency is 80 MHz. I want to set that frequency for SPI4 , but uanble to set how I can set the 80 Mhz frequency to SPI4. How can I set that if I set the 120 MHZ clock to SPI , but in prescaler it get divided by 2 so it set 60 MHZ, How can I solve that,please help me