drm/i915: Reduce severity for fixing up mistaken VBT tc->legacy_port

If the VBT assigned tc->legacy_port mismatches the live_status indicator
for the connector, we ignore the VBT directive and switch over to the HW
setting. This is not a driver error, unless we happen to misparse the
VBT or the live_status registers. However, for the system in CI where
the error is only reported on 1 port out of 4, the evidence indicates
the VBT is wrong. Stop flaging this as an error since the cause is
beyond our control, fixup the mistake and continue on.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201030153209.14808-1-chris@chris-wilson.co.uk