drm/i915/tc: Avoid using legacy AUX PW in TBT mode

For the ADL-P TBT mode the spec doesn't require blocking TC-cold by
using the legacy AUX power domain. To avoid the timeouts that this would
cause during PHY disconnect/reconnect sequences (which will be more
frequent after a follow-up change) use the TC_COLD_OFF power domain in
TBT mode on all platforms. On TGL this power domain blocks TC-cold via a
PUNIT command, while on other platforms the domain just takes a runtime
PM reference.

If the HPD live status indicates that the port mode needs to be reset
- for instance after switching from TBT to a DP-alt sink - still take
the AUX domain, since the IOM firmware handshake requires this.

v2: Rebased on v2 of the previous patch.

Cc: José Roberto de Souza <jose.souza@intel.com>
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/20210929132833.2253961-5-imre.deak@intel.com