Reset firmware when inference cancellation fails

If an inference fails to be cancelled and it is still in a pending
state, reset the whole firmware.  Indeed the assumption is that
something is at fault on the firmware side and it is not progressing.

Change-Id: I2f568b2167d86cda3cb96a5e83551b018f5fc55d
diff --git a/kernel/ethosu_device.h b/kernel/ethosu_device.h
index 7c6c99d..132dff2 100644
--- a/kernel/ethosu_device.h
+++ b/kernel/ethosu_device.h
@@ -89,4 +89,9 @@
  */
 void ethosu_dev_deinit(struct ethosu_device *edev);
 
+/**
+ * ethosu_firmware_reset() - Reset the device running firmware
+ */
+int ethosu_firmware_reset(struct ethosu_device *edev);
+
 #endif /* ETHOSU_DEVICE_H */