Use system include <foo.h> notation for libosmocore headers

the curent local copies of libosmocore headers + source is a temporary
hack anyway. We should instead rely on a system-wide install of
libosmocore cross-compiled for arm-none-eabi.  But leave that as a
second (later) step beyond this patch.

Change-Id: Ia63fd842d45a2b404233b4326050e7eda0604cf0
diff --git a/firmware/libcommon/source/pseudo_talloc.c b/firmware/libcommon/source/pseudo_talloc.c
index fd5cd13..c9722ba 100644
--- a/firmware/libcommon/source/pseudo_talloc.c
+++ b/firmware/libcommon/source/pseudo_talloc.c
@@ -3,7 +3,7 @@
 #include "talloc.h"
 #include "trace.h"
 #include "utils.h"
-#include "osmocom/core/utils.h"
+#include <osmocom/core/utils.h>
 
 #define NUM_RCTX_SMALL 10
 #define RCTX_SIZE_SMALL 348