fix: use SCP v2.11.0 for TC0

SCP-firmware no longer supports TC0, and has stopped distributing
binaries for it. We need to continue to maintain TC0 support for the
benefit of some SPM tests which still rely on it, so pin TC0 in the
CI to SCP-firmware v2.11.0.

Change-Id: I4d41a81763845b6e3baad5f1735296fb4b0aec47
Signed-off-by: Chris Kay <chris.kay@arm.com>
diff --git a/tc_utils.sh b/tc_utils.sh
index 20814da..634dac4 100644
--- a/tc_utils.sh
+++ b/tc_utils.sh
@@ -9,8 +9,15 @@
 
 tc_prebuilts="${tc_prebuilts:-$tfa_downloads/total_compute}"
 
-# Pre-built SCP binaries
-scp_prebuilts="${scp_prebuilts:-$scp_mcp_downloads}"
+case "${plat_variant}" in
+    0)
+        scp_prebuilts="${scp_prebuilts:-$scp_mcp_2_11_0_downloads}"
+        ;;
+
+    *)
+        scp_prebuilts="${scp_prebuilts:-$scp_mcp_downloads}"
+        ;;
+esac
 
 fvp_kernels[fvp-tc-kernel]="$tc_prebuilts/Image"
 fvp_initrd_urls[fvp-tc-ramdisk]="$tc_prebuilts/uInitrd-busybox.0x88000000"