The peripheral is the same in F3 so it should be similar, the exact values have to be calculated, details are in the STM32 Reference Manual.
The STM32CubeMX application can compute the TIMINGR value for you. Within STM32CubeMX, create a H7 project, configure the clock tree, then the I2C port you want to use, and you can generate pdf and text rapport where TIMINGR is calculated as a 32 bits constant.
The tool can even generate init code, but alas, not for ChibiOS :-/
Alexandre