edac: remove EDAC's experimental status

After 3 years, this is a patch to remove the EXPERIMENTAL tag on EDAC.  We
now have many module drivers submitters in EDAC and believe EDAC is no
longer EXPERIMENTAL

Signed-off-by: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>