drm/i915: don't limit Haswell CRT encoder to pipe A

drm/i915: don't limit Haswell CRT encoder to pipe A

This is a full revert of 59c859d6f2e78344945e8a8406a194156176bc4e:
    drm/i915: account for only one PCH receiver on Haswell

Now that the PCH code is fixed to be able use the only PCH transcoder
independently of the pipe and CPU transcoder, we can revert this.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
[danvet: Resolve conflict due to the rebasing of dinq on top of
drm-next.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>