drivers/tty/serial: add driver for the ESP32 UART

drivers/tty/serial: add driver for the ESP32 UART

Add driver for the UART controllers of the Espressif ESP32 and ESP32S3
SoCs. Hardware specification is available at the following URLs:

  https://www.espressif.com/sites/default/files/documentation/esp32_technical_reference_manual_en.pdf
  (Chapter 13 UART Controller)
  https://www.espressif.com/sites/default/files/documentation/esp32-s3_technical_reference_manual_en.pdf
  (Chapter 26 UART Controller)

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Link: https://lore.kernel.org/r/20231010085926.1021667-4-jcmvbkbc@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>