arm64: dts: mediatek: mt8195-cherry: Add MFG0 domain supply

MFG0 is the main power domain for the GPU and its surrounding glue
logic, and has a specific power rail.

Add its power supply on Cherry platforms and remove the now useless
(and wrong) regulator-always-on property from the vbuck1 regulator.
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi

@@ -476,6 +476,10 @@ pmic@34 {
 	};
 };
 
+&mfg0 {
+	domain-supply = <&mt6315_7_vbuck1>;
+};
+
 &mmc0 {
 	status = "okay";
 
@@ -1229,7 +1233,6 @@ mt6315_7_vbuck1: vbuck1 {
 				regulator-enable-ramp-delay = <256>;
 				regulator-ramp-delay = <6250>;
 				regulator-allowed-modes = <0 1 2>;
-				regulator-always-on;
 			};
 		};
 	};