Fix copy+paste mistake

Signed-off-by: Janos Follath <janos.follath@arm.com>
diff --git a/include/psa/crypto_extra.h b/include/psa/crypto_extra.h
index dcaf755..997fec0 100644
--- a/include/psa/crypto_extra.h
+++ b/include/psa/crypto_extra.h
@@ -1692,7 +1692,7 @@
  *                      #PSA_ALG_IS_PAKE(\p alg) is true).
  * \param primitive     A primitive of type ::psa_pake_primitive_t that is
  *                      compatible with algorithm \p alg.
- * \param output_step   A value of type ::psa_pake_step_t that is valid for the
+ * \param input_step    A value of type ::psa_pake_step_t that is valid for the
  *                      algorithm \p alg.
  * \return              A sufficient output buffer size for the specified
  *                      output, cipher suite and algorithm. If the cipher suite,