doxygen: fix parameter name typos and misused \p commands

Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/include/psa/crypto.h b/include/psa/crypto.h
index 8a05efd..6b06187 100644
--- a/include/psa/crypto.h
+++ b/include/psa/crypto.h
@@ -4407,9 +4407,9 @@
  * \retval #PSA_ERROR_BUFFER_TOO_SMALL
  *         The size of the \p signature buffer is too small. You can
  *         determine a sufficient buffer size by calling
- *         #PSA_SIGN_OUTPUT_SIZE(\c key_type, \c key_bits, \p alg)
+ *         #PSA_SIGN_OUTPUT_SIZE(\c key_type, \c key_bits, \c alg)
  *         where \c key_type and \c key_bits are the type and bit-size
- *         respectively of \p key.
+ *         respectively of \c key.
  *
  * \retval #PSA_ERROR_BAD_STATE
  *         An operation was not previously started on this context via