Add OneBit mode to HARDWARE menu. OneBit mode can help if your radio

has a slow inverter circuit by changing the UART sampling behaviour.

* It was found that the X9D+ and X7 (maybe others) have a slow inveter
that messes up reception of fast (400,000baud) UART signals.  On the
scope the rise time of the signal is very long.
* See RM0033 24.3.3 Receiver / Selecting the proper oversampling method.
Page 631.


Also note that reducing the pull-up resistor from 10k to 1k at R82
(X9D+) / R406 (X7) will also help with the rise times.  However on the
X7 changing the resistor is not enough, OneBit is needed too.

radio/src/targets/taranis/telemetry_driver.cpp

@@ -77,6 +77,9 @@ void telemetryPortInit(uint32_t baudrate, uint8_t mode)
   }
   USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
   USART_InitStructure.USART_Mode = USART_Mode_Tx | USART_Mode_Rx;
+  if (g_eeGeneral.uartSampleMode == UART_SAMPLE_MODE_ONEBIT) {
+    USART_OneBitMethodCmd(TELEMETRY_USART, ENABLE);
+  }
   USART_Init(TELEMETRY_USART, &USART_InitStructure);
   USART_Cmd(TELEMETRY_USART, ENABLE);