tls: fix guards for ECDSA support

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/library/ssl_ciphersuites.c b/library/ssl_ciphersuites.c
index e26ed1a..429d920 100644
--- a/library/ssl_ciphersuites.c
+++ b/library/ssl_ciphersuites.c
@@ -2022,7 +2022,7 @@
 #endif /* MBEDTLS_PK_C */
 
 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_ECDH_OR_ECDHE_1_2_ENABLED) || \
-    defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \
+    defined(MBEDTLS_KEY_EXCHANGE_ECDSA_CERT_REQ_ALLOWED_ENABLED) || \
     defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
 int mbedtls_ssl_ciphersuite_uses_ec(const mbedtls_ssl_ciphersuite_t *info)
 {
@@ -2040,7 +2040,7 @@
     }
 }
 #endif /* MBEDTLS_KEY_EXCHANGE_SOME_ECDH_OR_ECDHE_1_2_ENABLED ||
-        * MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
+        * MBEDTLS_KEY_EXCHANGE_ECDSA_CERT_REQ_ALLOWED_ENABLED ||
         * MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED*/
 
 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)