Introudce an include_libosmocore directory and move (updated) linuxlist there
diff --git a/firmware/src_simtrace/llist_irqsafe.h b/firmware/src_simtrace/llist_irqsafe.h
index b466939..9a59d3d 100644
--- a/firmware/src_simtrace/llist_irqsafe.h
+++ b/firmware/src_simtrace/llist_irqsafe.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#include "linuxlist.h"
+#include "osmocom/core/linuxlist.h"
 
 static inline void llist_add_tail_irqsafe(struct llist_head *_new,
 					  struct llist_head *head)