lora sx127x: Implement missing syncword support.

This work was funded through GitHub Sponsors.

Signed-off-by: Angus Gratton <[email protected]>

Author: projectgus

micropython/lora/lora-sx127x/lora/sx127x.py

@@ -519,6 +519,9 @@ def configure(self, lora_cfg):
 
         self._reg_update(_REG_MODEM_CONFIG3, update_mask, modem_config3)
 
+        if "syncword" in lora_cfg:
+            self._reg_write(_REG_SYNC_WORD, lora_cfg["syncword"])
+
     def _reg_write(self, reg, value):
         self._cs(0)
         if isinstance(value, int):