ncn8025: ncn8025_interrupt_active -> ncn8025_interrupt_level

The IRQ output of the NCN8025 doesn't really have an "active" state
but it's slightly more intricate.  To avoid confusion, let's just
provide a function to obtain the raw value (0=low / 1=high) and
let the user decide what to do with that

Change-Id: I752a84c67046b1d5f832cd1ef2070ec9b2489231
diff --git a/sysmoOCTSIM/ncn8025.h b/sysmoOCTSIM/ncn8025.h
index a2a6459..2e774a7 100644
--- a/sysmoOCTSIM/ncn8025.h
+++ b/sysmoOCTSIM/ncn8025.h
@@ -26,6 +26,6 @@
 
 int ncn8025_set(uint8_t slot, const struct ncn8025_settings *set);
 int ncn8025_get(uint8_t slot, struct ncn8025_settings *set);
-bool ncn8025_interrupt_active(uint8_t slot);
+bool ncn8025_interrupt_level(uint8_t slot);
 int ncn8025_init(unsigned int slot);
 void ncn8025_dump(const struct ncn8025_settings *set);