ipq806x: onhub: Enable adm_dma node

One of our SPI devices references this node, but we never enabled it.
This clutters up probe deferral logs.

(NB: this SPI device still doesn't have a real driver, so it's just here
for documentation and/or tinkering.)
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

target/linux/ipq806x/files/arch/arm/boot/dts/qcom-ipq8064-onhub.dtsi

@@ -288,6 +288,10 @@
 	};
 };
 
+&adm_dma {
+	status = "okay";
+};
+
 &gmac0 {
 	status = "okay";
 	phy-mode = "rgmii";