target/arm926ejs: fix memory leaks

The memory leaks detected and fixed are:
- arm register cache;
- EmbeddedICE register cache;
- arm_jtag_reset_callback internal data;
- struct arm926ejs_common.

Issue identified with valgrind.
Tested on SPEAr320 based on arm926ejs.

Change-Id: If2bed02c516051ce4d0eb29b204a3f3337fe5d6a
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5698
Tested-by: jenkins

src/target/arm7_9_common.c

@@ -2682,6 +2682,15 @@ int arm7_9_examine(struct target *target)
 	return retval;
 }
 
+void arm7_9_deinit(struct target *target)
+{
+	struct arm7_9_common *arm7_9 = target_to_arm7_9(target);
+
+	if (target_was_examined(target))
+		embeddedice_free_reg_cache(arm7_9->eice_cache);
+
+	arm_jtag_close_connection(&arm7_9->jtag_info);
+}
 
 int arm7_9_check_reset(struct target *target)
 {