chore(2.6): update CSS models and run configs

Update CSS-related models version to 11.15.26 as per currently
recommended RD/SGI FVP version for the release tag RD-INFRA-2021.09.17
Update CSS-related model configurations according to reference solutions
run configs for particular platforms.

Change-Id: Ibdceb089691a684ae049a286ca7a95208875c19b
Signed-off-by: Maksims Svecovs <maksims.svecovs@arm.com>
Signed-off-by: Vijayenthiran Subramaniam <vijayenthiran.subramaniam@arm.com>
diff --git a/model/css-sgi575.sh b/model/css-sgi575.sh
index 58d3045..adc38e3 100644
--- a/model/css-sgi575.sh
+++ b/model/css-sgi575.sh
@@ -1,21 +1,24 @@
 #!/usr/bin/env bash
 #
-# Copyright (c) 2019-2020 Arm Limited. All rights reserved.
+# Copyright (c) 2019-2021 Arm Limited. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
 
-set_model_path "$warehouse/SysGen/SubSystemModels/11.10/36/models/Linux64_GCC-6.4/FVP_CSS_SGI-575"
+set_model_path "$warehouse/SysGen/SubSystemModels/11.15/26/models/$model_flavour/FVP_CSS_SGI-575"
 
 cat <<EOF >"$model_param_file"
 -C board.flashloader0.fname=$fip_bin
 -C board.virtioblockdevice.image_path=$busybox_bin
--C css.cmn600.force_on_from_start=1
+-C css.cmn600.force_rnsam_internal=false
 -C css.cmn600.mesh_config_file=SGI-575_cmn600.yml
+-C css.gic_distributor.ITS-device-bits=20
 -C css.mcp.ROMloader.fname=$mcp_rom_bin
 -C css.pl011_uart_ap.unbuffered_output=1
 -C css.scp.ROMloader.fname=$scp_rom_bin
 -C css.trustedBootROMloader.fname=$bl1_bin
+-C soc.pl011_uart_mcp.unbuffered_output=1
+-C soc.pl011_uart0.enable_dc4=0
 -C soc.pl011_uart0.unbuffered_output=1
 -C soc.pl011_uart1.unbuffered_output=1
 --data css.scp.armcortexm7ct=$scp_ram_bin@$scp_ram_addr