drm/i915: Fix FEC pipe A vs. DDI A mixup

On pre-TGL FEC is a port level feature, not a transcoder
level feature, and it's DDI A which doesn't have it, not
trancoder A. Check for the correct thing when determining
whether FEC is supported or not.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230502143906.2401-5-ville.syrjala@linux.intel.com


Reviewed-by: Luca Coelho <luciano.coelho@intel.com>