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/plat/arm/board/n1sdp/n1sdp_pm.c b/plat/arm/board/n1sdp/n1sdp_pm.c
index 8d45354..d89fb05 100644
--- a/plat/arm/board/n1sdp/n1sdp_pm.c
+++ b/plat/arm/board/n1sdp/n1sdp_pm.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023, Arm Limited. All rights reserved.
+ * Copyright (c) 2023-2025, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -19,5 +19,4 @@
 void n1sdp_pwr_domain_off(const psci_power_state_t *target_state)
 {
 	css_pwr_domain_off(target_state);
-	plat_arm_gic_redistif_off();
 }