Interestingly, many modern "Motorola programming cables" do not actually use a native Motorola USB chip. They use common bridge chips like:
serial@ff020000 compatible = "motorola,motbsidcom"; reg = <0xff020000 0x1000>; interrupts = <9>; current-speed = <115200>; ; motbsidcom driver
Do not search for "motbsidcom" directly. Instead: reg = <