family: nrf52: correct out of date code to use discoverer method (#1454)

Ensure core discovery after mass erase on locked targets.

Co-authored-by: Mathis Dedial <[email protected]>

pyocd/target/family/target_nRF52.py

@@ -103,7 +103,7 @@ def check_flash_security(self):
                     raise exceptions.TargetError("unable to unlock device")
                 # Cached badness from create_ap run during AP lockout prevents create_cores from
                 # succeeding.
-                self.dp.create_1_ap(AHB_AP_NUM)
+                self._discoverer._create_1_ap(AHB_AP_NUM)
             else:
                 LOG.warning("%s APPROTECT enabled: not automatically unlocking", self.part_number)
         else: