drm/i915: remove unused dev_priv->no_aux_handshake

The last user of dev_priv->no_aux_handshake was removed in commit
3cf2efb1 ("Revert "drm/i915/dp: use VBT provided eDP params if
available""). Finally remove the leftovers.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/f1f0830bb43ddc6857d6a43e51c14b2f0c58c4e0.1565271681.git.jani.nikula@intel.com

drivers/gpu/drm/i915/display/intel_dp.c

@@ -4147,10 +4147,6 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp)
 	drm_dp_read_desc(&intel_dp->aux, &intel_dp->desc,
 			 drm_dp_is_branch(intel_dp->dpcd));
 
-	if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11)
-		dev_priv->no_aux_handshake = intel_dp->dpcd[DP_MAX_DOWNSPREAD] &
-			DP_NO_AUX_HANDSHAKE_LINK_TRAINING;
-
 	/*
 	 * Read the eDP display control registers.
 	 *

drivers/gpu/drm/i915/i915_drv.h

@@ -1483,9 +1483,6 @@ struct drm_i915_private {
 	/* backlight registers and fields in struct intel_panel */
 	struct mutex backlight_lock;
 
-	/* LVDS info */
-	bool no_aux_handshake;
-
 	/* protects panel power sequencer state */
 	struct mutex pps_mutex;