ssl-opt.sh: Fix MBEDTLS_ENTROPY_C dependency adjustment

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 220e897..140409c 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -485,6 +485,7 @@
         *"programs/ssl/ssl_client1 "*)
             requires_config_enabled MBEDTLS_CTR_DRBG_C
             requires_config_enabled MBEDTLS_PSA_CRYPTO_C
+            requires_config_disabled MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG
             requires_config_enabled MBEDTLS_PEM_PARSE_C
             requires_config_enabled MBEDTLS_SSL_CLI_C
             requires_certificate_authentication
@@ -495,6 +496,7 @@
         *"programs/ssl/ssl_server "*)
             requires_config_enabled MBEDTLS_CTR_DRBG_C
             requires_config_enabled MBEDTLS_PSA_CRYPTO_C
+            requires_config_disabled MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG
             requires_config_enabled MBEDTLS_PEM_PARSE_C
             requires_config_enabled MBEDTLS_SSL_SRV_C
             requires_certificate_authentication