feat(gicv5): add a barebones GICv5 driver

This is the absolute minimum that's needed to compile an NS-only build
end exit out of EL3. The GIC is not used and/or configured in any way
but all the necessary hooks are populated.

Notably, SCR_EL3.FIQ becomes RES1 as GICv5 behaves in a similar manner
to a GICv3 with FIQ set.

Change-Id: Idae52b9df97f4ca2996b2dcd1e5efc45478a43f2
Co-developed-by: Achin Gupta <achin.gupta@arm.com>
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
diff --git a/include/bl31/interrupt_mgmt.h b/include/bl31/interrupt_mgmt.h
index 8b9dfb6..e228495 100644
--- a/include/bl31/interrupt_mgmt.h
+++ b/include/bl31/interrupt_mgmt.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2022, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2024, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -16,7 +16,8 @@
 #define INTR_TYPE_S_EL1			U(0)
 #define INTR_TYPE_EL3			U(1)
 #define INTR_TYPE_NS			U(2)
-#define MAX_INTR_TYPES			U(3)
+#define INTR_TYPE_RL			U(3)
+#define MAX_INTR_TYPES			U(4)
 #define INTR_TYPE_INVAL			MAX_INTR_TYPES
 
 /* Interrupt routing modes */