mei: docs: add hdcp documentation

1. Add a short ducumentation for MEI HDCP driver,
and fix DOC comments in drivers/misc/mei/hdcp/mei_hdcp.c

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/hdcp/mei_hdcp.c

@@ -2,7 +2,7 @@
 /*
  * Copyright © 2019 Intel Corporation
  *
- * Mei_hdcp.c: HDCP client driver for mei bus
+ * mei_hdcp.c: HDCP client driver for mei bus
  *
  * Author:
  * Ramalingam C <ramalingam.c@intel.com>
@@ -11,12 +11,9 @@
 /**
  * DOC: MEI_HDCP Client Driver
  *
- * This is a client driver to the mei_bus to make the HDCP2.2 services of
- * ME FW available for the interested consumers like I915.
- *
- * This module will act as a translation layer between HDCP protocol
- * implementor(I915) and ME FW by translating HDCP2.2 authentication
- * messages to ME FW command payloads and vice versa.
+ * The mei_hdcp driver acts as a translation layer between HDCP 2.2
+ * protocol  implementer (I915) and ME FW by translating HDCP2.2
+ * negotiation messages to ME FW command payloads and vice versa.
  */
 
 #include <linux/module.h>