drm/i915/power: Use intel_encoder_is_tc()

drm/i915/power: Use intel_encoder_is_tc()

Starting with Xe3p_LPD, when intel_phy_is_tc() returns true, it does
not necessarily mean that the port is connected to a PHY in the Type-C
subsystem.  The reason is that there is now a VBT field called
dedicated_external that will indicate that a Type-C capable port is
connected to a (most likely) combo/dedicated PHY.  When that's the case,
we must not do the extra programming required for Type-C connections.

In an upcoming change, we will modify intel_encoder_is_tc() to take the
VBT field dedicated_external into consideration.  Update
intel_display_power_well.c to use that function instead of
intel_phy_is_tc().

Note that, even though icl_aux_power_well_{enable,disable} are not part
of Xe3p_LPD's display paths, we modify them anyway for uniformity.

v2:
  - Add and use icl_aux_pw_is_tc_phy() helper to avoid explicit encoder
    lookup. (Imre)

Cc: Imre Deak <imre.deak@intel.com>
Cc: Shekhar Chauhan <shekhar.chauhan@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com> # v1
Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20251202012306.9315-3-matthew.s.atwood@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>