drm/i915/bios: parse DDI ports also for CHV for HDMI DDC pin and DP AUX channel

drm/i915/bios: parse DDI ports also for CHV for HDMI DDC pin and DP AUX channel

BugLink: http://bugs.launchpad.net/bugs/1724669
commit ea850f64c2722278f150dc11de2141baeb24211c upstream.

While technically CHV isn't DDI, we do look at the VBT based DDI port
info for HDMI DDC pin and DP AUX channel. (We call these "alternate",
but they're really just something that aren't platform defaults.)

In commit e4ab73a13291 ("drm/i915: Respect alternate_ddc_pin for all DDI
ports") Ville writes, "IIRC there may be CHV system that might actually
need this."

I'm not sure why there couldn't be even more platforms that need this,
but start conservative, and parse the info for CHV in addition to DDI.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100553
Reported-by: Marek Wilczewski <mw@3cte.pl>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/d0815082cb98487618429b62414854137049b888.1506586821.git.jani.nikula@intel.com
(cherry picked from commit 348e4058ebf53904e817eec7a1b25327143c2ed2)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>