sx126x: move RadioController into separate file for clarity

Signed-off-by: deadprogram <ron@hybridgroup.com>

sx126x/radiocontrol.go

@@ -0,0 +1,13 @@
+package sx126x
+
+// SX126X radio transceiver has several pins that control
+// RF_IN, RF_OUT, NSS, and BUSY.
+// This interface allows the creation of struct
+// that can drive the RF Switch (Used in Lora RX and Lora Tx)
+type RadioController interface {
+	Init() error
+	SetRfSwitchMode(mode int) error
+	SetNss(state bool) error
+	WaitWhileBusy() error
+	SetupInterrupts(handler func()) error
+}