EDAC, fsl-ddr: Separate FSL DDR driver from MPC85xx

The mpc85xx-compatible DDR controllers are used on ARM-based SoCs too.
Carve out the DDR part from the mpc85xx EDAC driver in preparation to
support both architectures.

Signed-off-by: York Sun <york.sun@nxp.com>
Cc: Johannes Thumshirn <morbidrsa@gmail.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: oss@buserror.net
Cc: stuart.yoder@nxp.com
Link: http://lkml.kernel.org/r/1470946525-3410-1-git-send-email-york.sun@nxp.com


Signed-off-by: Borislav Petkov <bp@suse.de>