drm/i915: Use correct pipe config to update pll dividers. V2

Use the new pipe config values to calculate the updated pll dividers.

This regression was introduced in

commit 0dbdf89f27b17ae1eceed6782c2917f74cbb5d59
Author: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Date:   Wed Oct 29 11:32:33 2014 +0200

    drm/i915: Add infrastructure for choosing DPLLs before disabling crtcs

	and

	commit 00d958817dd3daaa452c221387ddaf23d1e4c06f
	Author: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
	Date:   Wed Oct 29 11:32:36 2014 +0200

	    drm/i915: Covert remaining platforms to choose DPLLS before disabling CRTCs

v2: Use intel_pipe_will_have_type() to look at new configuration - Ander

Signed-off-by: Bob Paauwe <bob.j.paauwe@intel.com>
CC: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Tested-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>