timer/linux: Add missing header

Signed-off-by: Joshua Hursey <[email protected]>

Author: jjhursey

opal/mca/timer/linux/timer_linux_component.c

@@ -15,6 +15,7 @@
  * Copyright (c) 2015-2016 Los Alamos National Security, LLC. All rights
  *                         reserved.
  * Copyright (c) 2015 Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2017      IBM Corporation.  All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -30,6 +31,7 @@
 #include "opal/mca/timer/base/base.h"
 #include "opal/mca/timer/linux/timer_linux.h"
 #include "opal/constants.h"
+#include "opal/util/show_help.h"
 
 static opal_timer_t opal_timer_base_get_cycles_sys_timer(void);
 static opal_timer_t opal_timer_base_get_usec_sys_timer(void);