tls: fix guards for legacy ECDH contexts

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 96d268e..2b0b7f1 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -752,10 +752,10 @@
 #endif
 
 #if !defined(MBEDTLS_USE_PSA_CRYPTO) && \
-    defined(MBEDTLS_KEY_EXCHANGE_SOME_ECDH_OR_ECDHE_ANY_ENABLED)
+    defined(MBEDTLS_KEY_EXCHANGE_SOME_ECDH_OR_ECDHE_1_2_ENABLED)
     mbedtls_ecdh_context ecdh_ctx;              /*!<  ECDH key exchange       */
 #endif /* !MBEDTLS_USE_PSA_CRYPTO &&
-          MBEDTLS_KEY_EXCHANGE_SOME_ECDH_OR_ECDHE_ANY_ENABLED */
+          MBEDTLS_KEY_EXCHANGE_SOME_ECDH_OR_ECDHE_1_2_ENABLED */
 
 #if defined(PSA_WANT_ALG_ECDH) && defined(PSA_WANT_ALG_FFDH)
 #if (MBEDTLS_PSA_MAX_FFDH_PUBKEY_LENGTH >= MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH)