baytrail: initialize punit

The punit is responsible for a number of things. Without
performing the sequence included it won't change processor
frequency when requested and apparently there are some bizarre
hangs introduced if this sequence isn't included either. Lastly,
this needs to come after microcode has been loaded. As that is
done in bootblock the ordering is correct.

One other side effect is that this fixes the graphics devices'
device id. Before it was showing up as the same device id of the
SoC transaction router.

TEST=Built and booted.

Change-Id: Ib7be1d4b365e9a45647c778ee5f91de497c55bf1
Signed-off-by: Aaron Durbin <>
Reviewed-by: Shawn Nematbakhsh <>
3 files changed