UPSTREAM: drm/i915: s/intel_gen4_compute_page_offset/intel_compute_tile_offset/

Since intel_gen4_compute_page_offset() can now handle tiling formats
all the way down to gen2, rename it to intel_compute_tile_offset().
Not that we actually use it on gen2/3 since there's no DSPSURF etc.
registers which would take a page aligned address.

v2: s/page/tile/ (Daniel)

Signed-off-by: Ville Syrjl <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1452625717-9713-7-git-send-email-ville.syrjala@linux.intel.com

BUG=chrome-os-partner:45364,chrome-os-partner:52008
TEST=Hot plugging 4K displays via HDMI/DP to Skl systems should not cause
TEST=flicker.

(cherry picked from commit ce1e5c140ce945ef6fc4ee4803f0c2f774873d8f)
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>

Change-Id: Ie15fd981bff749151cca95f3cc5c36c089744ec5
Reviewed-on: https://chromium-review.googlesource.com/359633
Commit-Ready: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Tested-by: Prathyushi Nangia <prathyushi.nangia@intel.com>
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
3 files changed