stm32/uart: Use timeout_char even with CTS enabled.

When timeout=0 (non-blocking mode) the UART should still wait for each
character to go out.  Otherwise non-blocking mode with CTS enabled is
useless because it can only write one character at a time.

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

ports/stm32/uart.c

@@ -1069,11 +1069,6 @@ size_t uart_tx_data(machine_uart_obj_t *self, const void *src_in, size_t num_cha
     }
 
     uint32_t timeout;
-    if (self->uartx->CR3 & USART_CR3_CTSE) {
-        // CTS can hold off transmission for an arbitrarily long time. Apply
-        // the overall timeout rather than the character timeout.
-        timeout = self->timeout;
-    } else {
     #if defined(STM32G4)
     // With using UART FIFO, the timeout should be long enough that FIFO becomes empty.
     // Since previous data transfer may be ongoing, the timeout must be multiplied
@@ -1088,7 +1083,6 @@ size_t uart_tx_data(machine_uart_obj_t *self, const void *src_in, size_t num_cha
     // to be transferred to the data register, and then to be transmitted.
     timeout = 2 * self->timeout_char;
     #endif
-    }
 
     const uint8_t *src = (const uint8_t *)src_in;
     size_t num_tx = 0;