Remove SERIAL_FC from target.json on TT_M3HQ

Development board TT_M3HQ doesn't have CTS/RTS on its pinout.
If that is not the case PinMap_UART_RTS should be created.

Author: Tharazi97

targets/targets.json

@@ -8812,7 +8812,6 @@
             "PWMOUT",
             "RTC",
             "SERIAL",
-            "SERIAL_FC",
             "SLEEP",
             "SPI",
             "SPISLAVE",