ssl-opt: add a check for PSA computation of digest of ServerKeyExchange

diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 2ccecc4..30753b7 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -765,6 +765,7 @@
                 -C "Failed to setup PSA-based cipher context"\
                 -S "Failed to setup PSA-based cipher context"\
                 -s "Protocol is TLSv1.2" \
+                -c "Perform PSA-based computation of digest of ServerKeyExchange" \
                 -S "error" \
                 -C "error"
 }