refactor(hisilicon): console runtime switch on bl31 exit

TF-A plans to move the console_flush() and
console_switch_state(CONOSLE_FLAG_RUNTIME) calls to bl31_main() just
before BL31 exits.

For now we are mimicking the generic implementation by calling flush
and changing the console state to runtime at the end of
bl31_plat_runtime_setup() for each platform. This is so that each
platform can test it prior to moving flush and switch to bl31_main().

This patch affects the Hisilicon SoCs (poplar, hikey, hikey960).

Change-Id: I0cbb0644377f663e880310362abb4308e24f0cef
Signed-off-by: Salman Nabi <salman.nabi@arm.com>
diff --git a/plat/hisilicon/hikey/hikey_bl31_setup.c b/plat/hisilicon/hikey/hikey_bl31_setup.c
index 7d008e7..3bcb583 100644
--- a/plat/hisilicon/hikey/hikey_bl31_setup.c
+++ b/plat/hisilicon/hikey/hikey_bl31_setup.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2024, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -152,4 +152,6 @@
 
 void bl31_plat_runtime_setup(void)
 {
+	console_flush();
+	console_switch_state(CONSOLE_FLAG_RUNTIME);
 }