stm32/boards/NUCLEO_WB55: Enable LPUART1 on PA2/PA3.

Signed-off-by: Damien George <damien@micropython.org>

ports/stm32/boards/NUCLEO_WB55/mpconfigboard.h

@@ -22,6 +22,8 @@
 // UART buses
 #define MICROPY_HW_UART1_TX         (pin_B6)
 #define MICROPY_HW_UART1_RX         (pin_B7)
+#define MICROPY_HW_LPUART1_TX       (pin_A2)
+#define MICROPY_HW_LPUART1_RX       (pin_A3)
 // USART 1 is connected to the virtual com port on the ST-LINK
 #define MICROPY_HW_UART_REPL        PYB_UART_1
 #define MICROPY_HW_UART_REPL_BAUD   115200