Please have aread of https://www.morsemicro.com/resources/appnotes/MM_APPNOTE-24_Linux_Porting_Guide.pdf, and take a look at the Raspberry Pi build thread on this forum.
USB is much easier than SDIO and SPI, and won’t require device tree changes.
Note that the document doesn’t contain information specific for the USB dongle. When compiling the morse_driver, you will need to add CONFIG_MORSE_USB=y to the list of compile time definitions for the driver.
I’ll prod someone to get the porting guide updated, it needs an update to our new style anyway.