Enable -Wshadow always

Variable shadowing is, according to the C standard, permitted and valid
behaviour. However, allowing a local variable to take the same name as a
global one can cause confusion and can make refactoring and bug hunting
more difficult.

This patch moves -Wshadow from WARNING2 into the general warning group
so it is always used. It also fixes all warnings that this introduces
by simply renaming the local variable to a new name

Change-Id: I6b71bdce6580c6e58b5e0b41e4704ab0aa38576e
Signed-off-by: Justin Chadwell <justin.chadwell@arm.com>
diff --git a/plat/mediatek/mt8173/drivers/spm/spm_suspend.c b/plat/mediatek/mt8173/drivers/spm/spm_suspend.c
index 5021695..838455d 100644
--- a/plat/mediatek/mt8173/drivers/spm/spm_suspend.c
+++ b/plat/mediatek/mt8173/drivers/spm/spm_suspend.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -239,13 +239,13 @@
 /*
  * go_to_sleep_before_wfi() - trigger SPM to enter suspend scenario
  */
-static void go_to_sleep_before_wfi(const unsigned int spm_flags)
+static void go_to_sleep_before_wfi(const unsigned int flags_spm)
 {
 	struct pwr_ctrl *pwrctrl;
 
 	pwrctrl = &spm_ctrl;
 
-	set_pwrctrl_pcm_flags(pwrctrl, spm_flags);
+	set_pwrctrl_pcm_flags(pwrctrl, flags_spm);
 
 	spm_set_sysclk_settle();