bsps: Move bspstart.c to bsps

This patch is a part of the BSP source reorganization.

Update #3285.

bsps/shared/start/bspstart-empty.c

@@ -0,0 +1,20 @@
+/*
+ *  COPYRIGHT (c) 1989-2008.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.org/license/LICENSE.
+ */
+
+#include <bsp.h>
+#include <bsp/bootcard.h>
+
+/*
+ * This routine would usually do the bulk of the system initialization.
+ * But if a BSP doesn't need to do anything, it can use this version.
+ */
+
+void bsp_start( void )
+{
+}