MFC r200053,200091: ichsmb: drop default attachment to generic smbus hw
MFC r200053,200091: ichsmb: drop default attachment to generic smbus hw

Note that r200091 completely overrides r200053 and the merge of the
former is recorded for bookkeeping only.
r200091 won't be merged to 'more stable' branche(s) because of the POLA.

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase