arm64: dts: mt6358: Add the compatible for the regulators

The regulators are expected to be instantiated with matching the
device-tree compatible, so add the proper compatible name under the
regulators node.
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Hsin-Yi Wang <hsinyi@chromium.org>
Link: https://lore.kernel.org/r/20200625101757.101775-3-enric.balletbo@collabora.comSigned-off-by: Matthias Brugger <matthias.bgg@gmail.com>

arch/arm64/boot/dts/mediatek/mt6358.dtsi

@@ -16,6 +16,8 @@ mt6358codec: mt6358codec {
 		};
 
 		mt6358regulator: mt6358regulator {
+			compatible = "mediatek,mt6358-regulator";
+
 			mt6358_vdram1_reg: buck_vdram1 {
 				regulator-name = "vdram1";
 				regulator-min-microvolt = <500000>;