robert-hh 988b6e2dae renesas-ra: Add the UART methods uart.txdone() and uart.flush().
This required to add two functions down the stack to uart.c and ra.sci.c.

- One for telling, whther the transmission is busy.
- One for reporting the size of the TX buffer.

Tested with a EK-RA6M2 board.
2022-12-15 12:09:34 +01:00
..