drm/i915/edp: Increase T12 panel delay to 900 ms to fix DP AUX CH timeouts

This patch fixes the DP AUX CH timeouts observed during CI runs causing
CI Failures on a specific PCI device. This issue was fixed previously
by adding a quirk but looks like we need to increase this delay even more
in order to get rid all the DP AUX CH timeouts.

Fixes: c99a259b4b ("drm/i915/edp: Add a T12 panel delay quirk to fix
DP AUX CH timeouts")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101144
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
Cc: Clinton Taylor <clinton.a.taylor@intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Tomi Sarvela <tomi.p.sarvela@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1502823591-25310-1-git-send-email-manasi.d.navare@intel.com
(cherry picked from commit e8f345e08d)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/i915/intel_dp.c

@@ -5273,7 +5273,7 @@ intel_dp_init_panel_power_sequencer(struct drm_device *dev,
 	 * seems sufficient to avoid this problem.
 	 */
 	if (dev_priv->quirks & QUIRK_INCREASE_T12_DELAY) {
-		vbt.t11_t12 = max_t(u16, vbt.t11_t12, 800 * 10);
+		vbt.t11_t12 = max_t(u16, vbt.t11_t12, 900 * 10);
 		DRM_DEBUG_KMS("Increasing T12 panel delay as per the quirk to %d\n",
 			      vbt.t11_t12);
 	}