fix(psci): initialise variables

When building with LTO, GCC is uncomfortable that these variables are
uninitialised and complains that they may be used before they are
initialised. Set them to 0 as there are plenty of asserts to make sure
these branches cannot be taken.

Change-Id: Ic1f05e77252e93bdafab033dcb24ad42856ebf9a
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
diff --git a/lib/psci/psci_main.c b/lib/psci/psci_main.c
index 34de10f..34668ea 100644
--- a/lib/psci/psci_main.c
+++ b/lib/psci/psci_main.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2024, Arm Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2025, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -305,7 +305,7 @@
 int psci_migrate(u_register_t target_cpu)
 {
 	int rc;
-	u_register_t resident_cpu_mpidr;
+	u_register_t resident_cpu_mpidr = 0;
 
 	/* Validate the target cpu */
 	if (!is_valid_mpidr(target_cpu))
@@ -347,7 +347,7 @@
 
 u_register_t psci_migrate_info_up_cpu(void)
 {
-	u_register_t resident_cpu_mpidr;
+	u_register_t resident_cpu_mpidr = 0;
 	int rc;
 
 	/*