dts: vendor-prefixes: add ftdi
dts: vendor-prefixes: add ftdi

We have a ftdi,ft800 binding, and it's easy to imagine additional
bindings coming in the future since their USB/UART chips are very
commonly used.

I didn't find anything in Linux for this vendor.

Signed-off-by: Martí Bolívar <9d90ac4c7bf6a305f6bfd81a23c7859bc883380e@nordicsemi.no>

galak/zephyr,galak/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr