Revert "mb/aopen/dxplplusu: Remove board"

This reverts commit eb76a455cd39ec59b7f2ba28baeec9538befd59e
and applies minor fixes to make it build again.

PARALLEL_MP was working prior to board removal and no
relevant SMI handlers were implemented. So NO_SMM choice
is now selected.

Change-Id: Ia1cd02278240d1b5d006fb2a7730d3d86390f85b
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/69339
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
diff --git a/src/mainboard/aopen/dxplplusu/acpi/scsi.asl b/src/mainboard/aopen/dxplplusu/acpi/scsi.asl
new file mode 100644
index 0000000..c34dd4e
--- /dev/null
+++ b/src/mainboard/aopen/dxplplusu/acpi/scsi.asl
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+/* PCI-X devices 04:04.0 and 04:04.1 : AIC-7902W
+ * U320 SCSI dual-channel controller
+ */
+
+Device (SCS0)
+{
+	Name (_ADR, 0x00040000)
+	OperationRegion (SCSC, PCI_Config, 0x00, 0x0100)
+	Field (SCSC, ByteAcc, NoLock, Preserve)
+	{
+		Offset (0x2C),   SID,   32,
+		Offset (0xE0),   PMC,   8,
+		Offset (0xFF),   IDW,   8
+	}
+}
+
+Device (SCS1)
+{
+	Name (_ADR, 0x00040001)
+	OperationRegion (SCSC, PCI_Config, 0x00, 0x0100)
+	Field (SCSC, ByteAcc, NoLock, Preserve)
+	{
+		Offset (0x2C),   SID,   32,
+		Offset (0xE0),   PMC,   8,
+		Offset (0xFF),   IDW,   8
+	}
+}