See the Section 2.3 of the LS1028ARDB board Reference Manual:
https://www.nxp.com/webapp/Download?colCode=LS1028ARDBRM
This Section contains the following:
The 5P49V5907B520NDGI is a programmable clock generator that generates most of the clocks. Clock configurations are stored in its one-time programmable (OTP) memory. The configuration in volatile memory can be changed through the I2C1_CH1 interface. The device is accessible at 0x6A I2C 7-bit address. The frequencies are generated from a 25 MHz crystal (603-25-261 from FOX Electronics).
See also documentation for the 5P49V5907:
https://www.renesas.com/in/en/document/dst/5p49v5907-datasheet?language=en