LF-3367-1: drm: cdns_hdmi: HDCP_STATE_DISABLING may missed by check link

LF-3367-1: drm: cdns_hdmi: HDCP_STATE_DISABLING may missed by check link

Polling thread check_work is designed to handle all hdcp state change.
In HDCP disable function, check_work thread will be stopped after
hdcp.state is set to HDCP_STATE_DISABLING. check_work thread may miss
the state change, call check link function make sure HDCP_STATE_DISABLING
state is properly handled.

Signed-off-by: Sandor Yu <Sandor.yu@nxp.com>
Reviewed-by: Robby Cai <robby.cai@nxp.com>
Acked-by: Jason Liu <jason.hui.liu@nxp.com>