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

firmware/libboard/qmod/source/board_qmod.c

@@ -9,7 +9,7 @@
 #include "sim_switch.h"
 #include "boardver_adc.h"
 #include "card_pres.h"
-#include "osmocom/core/timer.h"
+#include <osmocom/core/timer.h>
 #include "usb_buf.h"
 
 static const Pin pin_hubpwr_override = PIN_PRTPWR_OVERRIDE;

firmware/libboard/qmod/source/wwan_perst.c

@@ -9,7 +9,7 @@
 #include "board.h"
 #include "trace.h"
 #include "wwan_perst.h"
-#include "osmocom/core/timer.h"
+#include <osmocom/core/timer.h>
 
 struct wwan_perst {
 	uint8_t idx;