drm/i915: merge get_gtt_alignment/get_unfenced_gtt_alignment()

The two functions are rather similar, so merge them.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --cc drivers/gpu/drm/i915/i915_drv.h
Simple merge

diff --cc drivers/gpu/drm/i915/i915_gem.c
Simple merge

diff --cc drivers/gpu/drm/i915/i915_gem_tiling.c
Simple merge