There are STM32 families where all models use only the Synopsys DWC2 USB OTG core while others completely use only the USB Device FS core. For these families then either the driver `drivers/usbdev_synopsys_dwc2` or the driver `cpu/stm32/periph/usbdev` is used depending on the respective family. However, the STM32 families F1 and L4 use both cores. The correct driver must therefore be selected depending on the CPU line or CPU model.
`CFG_TUD_MAX_SPEED` definition isn't required since tinyUSB derives it from `TUD_RHPORT_MODE` if not defined or uses the maximum speed the MCU supports by default.
The cpus for the sam*xpro series have some differences in make and Kconfig
Kconfig seems to be more verbose and make assumes samr34-xpro just uses saml21
