ARM: dt: dove: add GPU power domain description

Add the description of the GPU power domain to the PMU DT entry.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NGregory CLEMENT <gregory.clement@free-electrons.com>

arch/arm/boot/dts/dove.dtsi

@@ -438,6 +438,13 @@
 						marvell,pmu_iso_mask = <0x00000001>;
 						resets = <&pmu 16>;
 					};
+
+					gpu_domain: gpu-domain {
+						#power-domain-cells = <0>;
+						marvell,pmu_pwr_mask = <0x00000004>;
+						marvell,pmu_iso_mask = <0x00000002>;
+						resets = <&pmu 18>;
+					};
 				};
 
 				thermal: thermal-diode@001c {