refactor: convert arm platforms to use the generic GIC driver

This reduces the code the platforms have to carry and makes their build
rules a bit simpler.

The main benefit is that plat_my_core_pos() no longer needs to be called
within the driver, helping with performance a bit.

Change-Id: I0b0d1d36d20d67c41c8c9dc14ade11bda6d4a6af
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
diff --git a/drivers/arm/css/scp/css_pm_scpi.c b/drivers/arm/css/scp/css_pm_scpi.c
index 02be070..781b216 100644
--- a/drivers/arm/css/scp/css_pm_scpi.c
+++ b/drivers/arm/css/scp/css_pm_scpi.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2025, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -121,12 +121,6 @@
 {
 	uint32_t response;
 
-	/*
-	 * Disable GIC CPU interface to prevent pending interrupt
-	 * from waking up the AP from WFI.
-	 */
-	plat_arm_gic_cpuif_disable();
-
 	/* Send the power down request to the SCP */
 	response = scpi_sys_power_state(scpi_system_shutdown);
 
@@ -143,12 +137,6 @@
 {
 	uint32_t response;
 
-	/*
-	 * Disable GIC CPU interface to prevent pending interrupt
-	 * from waking up the AP from WFI.
-	 */
-	plat_arm_gic_cpuif_disable();
-
 	/* Send the system reset request to the SCP */
 	response = scpi_sys_power_state(scpi_system_reboot);