drm/i915: Add HDCP 1.4 support for MST connectors

drm/i915: Add HDCP 1.4 support for MST connectors

Now that all the groundwork has been laid, we can turn on HDCP 1.4 over
MST. Everything except for toggling the HDCP signalling and HDCP 2.2
support is the same as the DP case, so we'll re-use those callbacks

Cc: Juston Li <juston.li@intel.com>
Reviewed-by: Anshuman Gupta <anshuman.gupta@intel.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191203173638.94919-12-sean@poorly.run
Link: https://patchwork.freedesktop.org/patch/msgid/20191212190230.188505-13-sean@poorly.run
Link: https://patchwork.freedesktop.org/patch/msgid/20200117193103.156821-13-sean@poorly.run
Link: https://patchwork.freedesktop.org/patch/msgid/20200218220242.107265-15-sean@poorly.run
Link: https://patchwork.freedesktop.org/patch/msgid/20200305201236.152307-17-sean@poorly.run
Link: https://patchwork.freedesktop.org/patch/msgid/20200429195502.39919-17-sean@poorly.run
Link: https://patchwork.freedesktop.org/patch/msgid/20200623155907.22961-18-sean@poorly.run
Changes in v2:
-Toggle HDCP from encoder disable/enable
-Don't disable HDCP on MST connector destroy, leave that for encoder
 disable, just ensure the check_work routine isn't running any longer
Changes in v3:
-Place the shim in the new intel_dp_hdcp.c file (Ville)
Changes in v4:
-Actually use the mst shim for mst connections (Juston)
-Use QUERY_STREAM_ENC_STATUS MST message to verify channel is encrypted
Changes in v5:
-Add sleep on disable signalling to match hdmi delay
Changes in v6:
-Disable HDCP over MST on GEN12+ since I'm unsure how it should work and I
 don't have hardware to test it
Changes in v7:
-Remove hdcp2 shims for MST in favor of skipping hdcp2 init (Ramalingam)
Changes in v8:
-None

Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200818153910.27894-18-sean@poorly.run