HAL_ChibiOS: added another uart to omnibusf4v6

for RC telemetry such as Hott telem

libraries/AP_HAL_ChibiOS/hwdef/omnibusf4v6/hwdef.dat

@@ -28,7 +28,7 @@ I2C_ORDER I2C1
 
 # order of UARTs     
 
-UART_ORDER OTG1 USART6 USART1 UART4 USART3
+UART_ORDER OTG1 USART6 USART1 UART4 USART3 USART2
 
 
 #PINS 
@@ -45,6 +45,8 @@ PB11 USART3_RX USART3
 # UART4 (only RX) #"TX" pin PA0 is used for RSSI_ADC_CHANNEL
 PA1 UART4_RX UART4 
 
+# transmit only usart2, for telemetry output (eg. Hott telem)
+PA2 USART2_TX USART2
 
 #adc
 PC1 BAT_CURR_SENS ADC1 SCALE(1)