ARM: dts: a20-wits-pro-a20-dkt: Enable AHCI

Enable ahci node for a20-wits-pro-a20-dkt, this would require since
we have DM_SCSI enabled on the respective SoC.

Right now, ahci enabled in -u-boot.dtsi and will remove once same
supported by Linux.

Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: NJagan Teki <jagan@amarulasolutions.com>

arch/arm/dts/sun7i-a20-wits-pro-a20-dkt-u-boot.dtsi

+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 Jagan Teki <jagan@amarulasolutions.com>
+ */
+
+#include "sunxi-u-boot.dtsi"
+
+&ahci {
+	status = "okay";
+};