feat(fvp): add stub platform function to get ACPI table region size

Introduces a stub platform function for FVP to retrieve the ACPI table
region size.

Change-Id: Icbf1ae0cb89c393502de2c2f4f66df6b510e6b81
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
diff --git a/plat/arm/board/fvp/fvp_drtm_stub.c b/plat/arm/board/fvp/fvp_drtm_stub.c
index e2bc516..213a7e3 100644
--- a/plat/arm/board/fvp/fvp_drtm_stub.c
+++ b/plat/arm/board/fvp/fvp_drtm_stub.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, Arm Limited. All rights reserved.
+ * Copyright (c) 2022-2025, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -33,3 +33,8 @@
 {
 	return 0ULL;
 }
+
+uint64_t plat_drtm_get_acpi_tables_region_size(void)
+{
+	return 0ULL;
+}