drivers/edac: mod edac_align_ptr function

Refactor the edac_align_ptr() function to reduce the noise of casting the
aligned pointer to the various types of data objects and modified its callers
to its new signature

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