drm/i915: Disable LVDS port after the pipe on PCH

drm/i915: Disable LVDS port after the pipe on PCH

Follow the correct pipe vs port disable sequence for the PCH LVDS
ports, ie. disable the port after the pipe.

Other PCH port were already converted in the following commits:
 65c202c55b43384e63fdebace4a10f4bc301ccd2 drm/i915: Disable CRT port after pipe on PCH platforms
 83606c5b90f6da61d63ae8a29c6332070f55f909 drm/i915: Disable SDVO port after the pipe on PCH platforms
 c332bfef8186843163f69095db30cbd7b4084cdf drm/i915: Disable HDMI port after the pipe on PCH platforms
 f9f34b7ca206bbe657d42708b4dbf9b32ea5426e drm/i915: Move DP port disable to post_disable for pch platforms
but LVDS was forgotten.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>