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

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: c99a259b4b5192ba ("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 e8f345e08d391827f2cba5d172af990cc7afb062)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>