drm/i915/cec: switch to setting physical address directly

Avoid parsing the EDID again for source physical address. Also gets rids
of a few remaining raw EDID usages.

Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: linux-media@vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Link: https://patchwork.freedesktop.org/patch/msgid/01a90c82c8a4f2fd945e0181ffeaca595928d19e.1692884619.git.jani.nikula@intel.com