EDAC, altera: Merge Stratix10 into the Arria10 SDRAM probe routine

Change Stratix10 regmap to use offsets from a base to match
the Arria10 regmap and allow re-use of the Arria10 functions.
Only the regmap initialization differs (Arria10 mmio_regmap
vs Stratix10 custom regmap).

Modify the SDRAM probe function to handle Stratix10. Remove the
Stratix10 offset defines if Arria10 can be used. Remove the unused
Stratix10 probe function.

Signed-off-by: Thor Thayer <thor.thayer@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: dinguyen@kernel.org
Cc: robh+dt@kernel.org
Cc: mark.rutland@arm.com
Cc: mchehab@kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-edac@vger.kernel.org
Link: https://lkml.kernel.org/r/1537883342-30180-5-git-send-email-thor.thayer@linux.intel.com