replacement of #4686 with a single doxygen fix

[lyakh]

1-to-1 copy of #4686 with a single diff

diff --git a/src/include/sof/ipc/common.h b/src/include/sof/ipc/common.h
index 5182b548e..84b155ff1 100644
--- a/src/include/sof/ipc/common.h
+++ b/src/include/sof/ipc/common.h
@@ -185,7 +185,7 @@ ipc_cmd_hdr *mailbox_validate(void);
  * any optional payload) is deserialized from the IPC HW by the platform
  * specific method.
  *
- * @param hdr Points to the IPC command header.
+ * @param _hdr Points to the IPC command header.
  */
 void ipc_cmd(ipc_cmd_hdr *_hdr);