Merge changes from topic "av/console-register" into integration

* changes:
  Console: Remove Arm console unregister on suspend
  Console: Allow to register multiple times

drivers/console/multi_console.c

@@ -20,8 +20,10 @@ int console_register(console_t *console)
 {
 	/* Assert that the struct is not on the stack (common mistake). */
 	assert((console < stacks_start) || (console >= stacks_end));
-	/* Assert that we won't make a circle in the list. */
-	assert(!console_is_registered(console));
+
+	/* Check that we won't make a circle in the list. */
+	if (console_is_registered(console) == 1)
+		return 1;
 
 	console->next = console_list;
 	console_list = console;

plat/arm/common/arm_console.c

 /*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -80,9 +80,7 @@ void arm_console_runtime_end(void)
 {
 	(void)console_flush();
 
-#if MULTI_CONSOLE_API
-	(void)console_unregister(&arm_runtime_console.console);
-#else
+#if !MULTI_CONSOLE_API
 	console_uninit();
-#endif /* MULTI_CONSOLE_API */
+#endif /* !MULTI_CONSOLE_API */
 }