Move all the EDAC core functionality behind CONFIG_EDAC and get rid of
that indirection. Update defconfigs which had it.

While at it, fix dependencies such that EDAC depends on RAS for the
tracepoints.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: linux-edac@vger.kernel.org