EDAC, ti: Add support for TI keystone and DRA7xx EDAC

TI Keystone and DRA7xx SoCs have support for EDAC on DDR3 memory that can
correct one bit errors and detect two bit errors. Add EDAC driver for this
feature which plugs into the generic kernel EDAC framework.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: linux-omap@vger.kernel.org
Link: http://lkml.kernel.org/r/1510578490-14510-1-git-send-email-t-kristo@ti.com


[ Add SPDX tag and make _emif_get_id() use edac_printk(). ]
Signed-off-by: Borislav Petkov <bp@suse.de>