MFC r303113: Cross-link some SMBus controller drivers man pages.

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Add information about the ICH6 and ICH7 being supported since recently.

ICH5 is also supported by ichsmb

Reflect support for 82801CA (ICH3) and 82801DC (ICH4) PCI chips.

Removed whitespace at end-of-line; no content changes. I simply did
cd src/share; find man[1-9] -type f|xargs perl -pi -e 's/[ \t]+$//'

BTW, what editors are the culprits? I'm using vim and it shows
me whitespace at EOL in troff files with a thick blue block...

Reviewed by: Silence from cvs diff -b
MFC after: 7 days

mdoc(7) police: removed HISTORY info from the .Os call.

Update @freebsd.org email addresses to @FreeBSD.org as is the
precedent.

.Os FreeBSD instead of just plain .Os

Submitted by: ru

Man page for the ichsmb SMBus controller driver.