Port for GD32E230 by Peter Schildmann

LCSC GD32E230 Dev Board (https://oshwlab.com/lckfb-team/lcsc-gd32e230-dev-board)

   - Equipped with a GD32E230C8T6 MCU
   - Uses the same pinout as the well-known Blue Pill board
   - Includes a CH340N USB-to-serial converter connected to MCU pins PA9 (TX) and PA10 (RX)
   - Features an ARM Cortex-M23 core, 8 KB RAM, and 64 KB Flash memory
   - Peripherals are very similar to those of the STM32F030, with some enhancements

The UART is configured for 8 data bits, no parity, and two stop bits, with a baud rate of 115200.

(The STM32F030 port was used as a starting point because it runs on the GD32E230,
with the exception of Flash programming.)
