drm: HDCP2.2 link check period

Time period for HDCP2.2 link check.
Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1550338640-17470-10-git-send-email-ramalingam.c@intel.com

include/drm/drm_hdcp.h

@@ -13,6 +13,7 @@
 
 /* Period of hdcp checks (to ensure we're still authenticated) */
 #define DRM_HDCP_CHECK_PERIOD_MS		(128 * 16)
+#define DRM_HDCP2_CHECK_PERIOD_MS		500
 
 /* Shared lengths/masks between HDMI/DVI/DisplayPort */
 #define DRM_HDCP_AN_LEN				8