drm/i915/adlp: Fix TypeC PHY-ready status readout

drm/i915/adlp: Fix TypeC PHY-ready status readout

The TCSS_DDI_STATUS register is indexed by tc_port not by the FIA port
index, fix this up. This only caused an issue on TC#3/4 ports in legacy
mode, as in all other cases the two indices either match (on TC#1/2) or
the TCSS_DDI_STATUS_READY flag is set regardless of something being
connected or not (on TC#1/2/3/4 in dp-alt and tbt-alt modes).

Reported-and-tested-by: Chia-Lin Kao (AceLan) <acelan.kao@canonical.com>
Fixes: 55ce306c2aa1 ("drm/i915/adl_p: Implement TC sequences")
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/4698
Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: <stable@vger.kernel.org> # v5.14+
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220126104356.2022975-1-imre.deak@intel.com
(cherry picked from commit 516b33460c5bee78b2055637b0547bdb0e6af754)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>