stm32/uart: Support board configs with CTS/RTS on UART6.

Author: dpgeorge

ports/stm32/uart.c

@@ -241,6 +241,16 @@ STATIC bool uart_init2(pyb_uart_obj_t *uart_obj) {
  irqn = USART6_IRQn;
  pins[0] = &MICROPY_HW_UART6_TX;
  pins[1] = &MICROPY_HW_UART6_RX;
+ #if defined(MICROPY_HW_UART6_RTS)
+ if (uart_obj->uart.Init.HwFlowCtl & UART_HWCONTROL_RTS) {
+ pins[2] = &MICROPY_HW_UART6_RTS;
+ }
+ #endif
+ #if defined(MICROPY_HW_UART6_CTS)
+ if (uart_obj->uart.Init.HwFlowCtl & UART_HWCONTROL_CTS) {
+ pins[3] = &MICROPY_HW_UART6_CTS;
+ }
+ #endif
  __USART6_CLK_ENABLE();
  break;
  #endif