edac: Drop __DATE__ usage

The kernel already prints its build timestamp during boot, no need to
repeat it in random drivers and produce different object files each
time.

Cc: Doug Thompson <dougthompson@xmission.com>
Cc: bluesmoke-devel@lists.sourceforge.net
Cc: linux-edac@vger.kernel.org
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>