aopen/dxplplusu: Disable HW scrubber

See initialize_ecc() for the awful hack that got us around cache-as-ram
being invalidated as we do ECC HW scrubbing. It once worked, but
compiler nowadays puts more registers on the stack.

Not much interest to try fix ECC for this particular board.

Change-Id: Ie6a09e28b0af5bbf2d68af72f5d98c03df33c402
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/15014
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Martin Roth <martinroth@google.com>

src/mainboard/aopen/dxplplusu/Kconfig

@@ -12,7 +12,7 @@ config BOARD_SPECIFIC_OPTIONS # dummy
 	select UDELAY_TSC
 	select HAVE_ACPI_TABLES
 	select BOARD_ROMSIZE_KB_512
-	select HW_SCRUBBER
+#	select HW_SCRUBBER
 
 config MAINBOARD_DIR
 	string