drm/i915: s/port/hpd_pin/ for icp+ ddi hpd bits

Use hpd_pin instead of port in the parametrized ICP+ DDI HPD
macros. Makes it clear what these refer to.

v2: Handle DG1

Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201028213323.5423-10-ville.syrjala@linux.intel.com