This patch adds the protocol for providing content-protection to a
client application. the content-protection here refers to the 'on the
wire protection' e.g. HDCP1.4 HDCP2.2.
The client application can request for the content-protection,
specifying the type of the content: TYPE-0 and TYPE-1 as defined in
HDCP. If all the connected hotpluggable displays support the rquested
content-type, the server sends an event for content-protection status
as "ON". Once the application receives this event it can show the
requested type of content.
In case if there is failure of content-protection for a given content-
type, the server sends content-protection status changed event as
"OFF". On receiving this event, the application can stop showing the
protected content.

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>