TGL reports incorrect values for device status in /sys/kernel/debug/dri/0/i915_sseu_status

It seems that the i915_sseu_status function hasn't been updated to take into account the new mapping of the bits in the powergating acknowledge register for TGL.

Probably a new gen12_sseu_device_status function is needed.

Or maybe it's time we get rid of the status part of this file as reading the powergating ack register only report correct values after a context's powergating request (so it will report invalid values if no context is run between when the GT waking up from PM and the time we read the register value from CPU).