drm/i915/dsi: Do display on sequence later on icl+

Doing the init OTP and display on DSI sequences back to back
doesn't really make any sense (a single sequence would suffice
then). Move the display on sequence to be done just before
backlight on, which is also what Windows does.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230608203057.23759-3-ville.syrjala@linux.intel.com