dts: bindings: serial: add Renesas R-Car SCIF
dts: bindings: serial: add Renesas R-Car SCIF

Renesas has Serial Communication Interface with
FIFO (SCIF) hardware block which allow asynchronous and
synchronous serial communication. The SCIF has 16-stage FIFO
buffers separately for transmissions and reception.

Signed-off-by: Aymeric Aillet <50ecb97e8539231bfe69207a233bb1580c5def34@iot.bzh>

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