psa_util: add algorithm's availability checks for MD conversion functions

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/include/mbedtls/psa_util.h b/include/mbedtls/psa_util.h
index 249b8d4..e8fb3de 100644
--- a/include/mbedtls/psa_util.h
+++ b/include/mbedtls/psa_util.h
@@ -152,21 +152,12 @@
  * \brief           This function returns the PSA algorithm identifier
  *                  associated with the given digest type.
  *
- * \param md_type   The type of digest to search for. Must not be NONE.
+ * \param md_type   The type of digest to search for.
  *
- * \warning         If \p md_type is \c MBEDTLS_MD_NONE, this function will
- *                  not return \c PSA_ALG_NONE, but an invalid algorithm.
- *
- * \warning         This function does not check if the algorithm is
- *                  supported, it always returns the corresponding identifier.
- *
- * \return          The PSA algorithm identifier associated with \p md_type,
- *                  regardless of whether it is supported or not.
+ * \return          The PSA algorithm identifier associated with \p md_type;
+ *                  #PSA_ALG_NONE if the algorithm is unuspported or invalid.
  */
-static inline psa_algorithm_t mbedtls_md_psa_alg_from_type(mbedtls_md_type_t md_type)
-{
-    return PSA_ALG_CATEGORY_HASH | (psa_algorithm_t) md_type;
-}
+psa_algorithm_t mbedtls_md_psa_alg_from_type(mbedtls_md_type_t md_type);
 
 /**
  * \brief           This function returns the given digest type
@@ -174,16 +165,10 @@
  *
  * \param psa_alg   The PSA algorithm identifier to search for.
  *
- * \warning         This function does not check if the algorithm is
- *                  supported, it always returns the corresponding identifier.
- *
  * \return          The MD type associated with \p psa_alg,
- *                  regardless of whether it is supported or not.
+ *                  #MBEDTLS_MD_NONE if the algorithm is unsupported or invalid.
  */
-static inline mbedtls_md_type_t mbedtls_md_type_from_psa_alg(psa_algorithm_t psa_alg)
-{
-    return (mbedtls_md_type_t) (psa_alg & PSA_ALG_HASH_MASK);
-}
+mbedtls_md_type_t mbedtls_md_type_from_psa_alg(psa_algorithm_t psa_alg);
 
 /**@}*/