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 b15f0afe71e71ecd3ae4a0ca169d3479df17a543:
    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>