Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Silicon Labs/Series1/EFM32GG11B/EFM32GG11B420F2048IM64/EMU/R5VOUTLEVEL#0x0
5V Regulator Voltage Select
5V Regulator Voltage
https://github.com/cmsis-svd/cmsis-svd-data