Fix parameter name signature_size for psa_asymmetric_verify

It should have been signature_length, following our conventions.
diff --git a/include/psa/crypto.h b/include/psa/crypto.h
index 4f1fd7d..62334dd 100644
--- a/include/psa/crypto.h
+++ b/include/psa/crypto.h
@@ -1791,7 +1791,7 @@
  * \param salt_length       Size of the \c salt buffer in bytes.
  *                          If \c salt is \c NULL, pass 0.
  * \param signature         Buffer containing the signature to verify.
- * \param signature_size    Size of the \c signature buffer in bytes.
+ * \param signature_length  Size of the \c signature buffer in bytes.
  *
  * \retval PSA_SUCCESS
  *         The signature is valid.
@@ -1812,7 +1812,7 @@
                                    const uint8_t *salt,
                                    size_t salt_length,
                                    const uint8_t *signature,
-                                   size_t signature_size);
+                                   size_t signature_length);
 
 #define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(key_type, key_bits, alg)     \
     (PSA_KEY_TYPE_IS_RSA(key_type) ?                                    \