STM32L476RG MCU of NUCLEO_L476RG board has 6 UART/USART units in total
(USART1, USART2, USART3, UART4, UART5 and LPUART1), but only UART2,
connected to REPL, was defined and available in Python code.
Defined are all 5 remaining UART/USART units including LPUART1.
Signed-off-by: Alexander Ziubin aziubin@googlemail.com