Hi @terbshaeuser,
Please find VIRT_I2C example at Code Aurora (this example is for L4.1498, but you can switch to another branch if needed). Also, you may also find relevant ecSPI examples within the Cortex M4 SDK for the i.MX 8QM MEK; please download SDK at: SDK Builder.
Just in case that you need to review more SCFW documentation you may want to get it from our SCFW porting kit. Our website, Linux Releases, allows you to download the specific SCFW porting kit for each BSP release.
Hope this helps!
Ruben