Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Silicon Labs/Series1/EFR32FG12P/EFR32FG12P231F512GM68/I2C1/ROUTEPEN#0x0
I/O Routing Pin Enable Register
SDA Pin Enable
SCL Pin Enable
https://github.com/cmsis-svd/cmsis-svd-data