drm/i915: Pass 90/270 vs. 0/180 rotation info for intel_gen4_compute_page_offset()

drm/i915: Pass 90/270 vs. 0/180 rotation info for intel_gen4_compute_page_offset()

The page aligned surface address calculation needs to know which way
things are rotated. The contract now says that the caller must pass the
rotate x/y coordinates, as well as the tile_height aligned stride in
the tile_height direction. This will make it fairly simple to deal with
90/270 degree rotation on SKL+ where we have to deal with the rotated
view into the GTT.

v2: Pass rotation instead of bool even thoughwe only care about 0/180 vs. 90/270
v3: Introduce intel_tile_dims(), and don't mix up different units so much
v4: Unconfuse bytes vs. pixels even more

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455569699-27905-4-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>