[Intel-gfx] add lpt_init_pch_refclk bike-sheds

[Damien Lespiau]

As Paulo is on holidays, here are the bikesheds as patches on top of his

commit 88ab6308995e7180d25489ef35e323fcb6373601
Author: Paulo Zanoni <paulo.r.zanoni at intel.com>
Date:   Sat Dec 1 12:04:25 2012 -0200

    drm/i915: add lpt_init_pch_refclk

As those changes are not tested (but hopefully should be straightforward to
counter review :) I've joined them as patches that can be squashed into his 
at will.

HTH,

--
Damien