EDAC, aspeed: Add an Aspeed AST2500 EDAC driver

Add support for the Aspeed AST2500 SoC.

Signed-off-by: Stefan M Schaeckeler <sschaeck@cisco.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Jeffery <andrew@aj.id.au>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-aspeed@lists.ozlabs.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: https://lkml.kernel.org/r/1547743097-5236-2-git-send-email-schaecsn@gmx.net