fixed guard position for doxygen

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/include/mbedtls/ecp.h b/include/mbedtls/ecp.h
index 0b72a83..8bddbae 100644
--- a/include/mbedtls/ecp.h
+++ b/include/mbedtls/ecp.h
@@ -1276,6 +1276,7 @@
 int mbedtls_ecp_write_key(mbedtls_ecp_keypair *key,
                           unsigned char *buf, size_t buflen);
 
+#if !defined(MBEDTLS_USE_PSA_CRYPTO)
 /**
  * \brief           This function checks that the keypair objects
  *                  \p pub and \p prv have the same group and the
@@ -1296,8 +1297,6 @@
  * \return          An \c MBEDTLS_ERR_ECP_XXX or an \c MBEDTLS_ERR_MPI_XXX
  *                  error code on calculation failure.
  */
-
-#if !defined(MBEDTLS_USE_PSA_CRYPTO)
 int mbedtls_ecp_check_pub_priv(
     const mbedtls_ecp_keypair *pub, const mbedtls_ecp_keypair *prv,
     int (*f_rng)(void *, unsigned char *, size_t), void *p_rng);