Add ichwd TCO version 3 support (Bay Trail / Rangeley...)

[fabient]

Summary

Patch from Cas-well to add support for

Test Plan

Tested on Rangeley / Baytrail and on ICH10 for regression.

[jhb]

I think this mostly looks fine. Just have one suggestion.

sys/dev/ichwd/ichwd.c

311

I would actually suggest that you leave the gcs macros with their existing names and add new ones for pmc that have a comment like this:

/* NB: TCO version 3 devices use the gcs_reg resource for the PMC register. */
#define ichwd_read_pmc_4(sc, off) \
        bus_read_4((sc)->gcs_res, (off))

And the same for ichwd_write_pmc_4(). I would then use the _gcs macros for TCO 2 devices and the _pmc macros for TCO 3 devices.

[fabient]

commited as r286890