drm/i915: Add render decompression support

SKL+ display engine can scan out certain kinds of compressed surfaces
produced by the render engine. This involved telling the display engine
the location of the color control surfae (CCS) which describes
which parts of the main surface are compressed and which are not. The
location of CCS is provided by userspace as just another plane with its
own offset.

Add the required stuff to validate the user provided AUX plane metadata
and convert the user provided linear offset into something the hardware
can consume.

Due to hardware limitations we require that the main surface and
the AUX surface (CCS) be part of the same bo. The hardware also
makes life hard by not allowing you to provide separate x/y offsets
for the main and AUX surfaces (excpet with NV12), so finding suitable
offsets for both requires a bit of work. Assuming we still want keep
playing tricks with the offsets. I've just gone with a dumb "search
backward for suitable offsets" approach, which is far from optimal,
but it works.

Also not all planes will be capable of scanning out compressed surfaces,
and eg. 90/270 degree rotation is not supported in combination with
decompression either.

This patch may contain work from at least the following people:
* Vandana Kannan <vandana.kannan@intel.com>
* Daniel Vetter <daniel@ffwll.ch>
* Ben Widawsky <ben@bwidawsk.net>

v2: Deal with display workarounds 0390, 0531, 1125 (Paulo)
v3: Pretend CCS tiles are regular 128 byte wide Y tiles (Jason)
    Put the AUX register defines to the correct place
    Fix up the slightly bogus rotation check
v4: Use I915_WRITE_FW() due to plane update locking changes
    s/return -EINVAL/goto err/ in intel_framebuffer_init()
    Eliminate a bunch hardcoded numbers in CCS code

v5: (By Ben)
conflict resolution +
-               res_blocks += fixed_16_16_to_u32_round_up(y_tile_minimum);
+               res_blocks += fixed16_to_u32_round_up(y_tile_minimum);

v6: (daniels) Fix botched commit message.

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Signed-off-by: Ville Syrjä <ville.syrjala@linux.intel.com>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net> (v1)
Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Stone <daniels@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170801165817.7063-1-ben@bwidawsk.net