arm64: dts: rockchip: Enable the GPU on quartzpro64

Following the approach used to enable the Mali GPU on the rk3588-evb1, [1]
do the same for the Pine64 QuartzPro64, which uses nearly identical hardware
design as the RK3588 EVB1.

The slight disadvantage is that the regulator coupling logic requires the
regulators to be always on, which is also noted in the comments.  This is
obviously something to be improved at some point in the future, but should
be fine for now, especially because the QuartzPro64 isn't a battery-powered
board, so low power consumption isn't paramount.

[1] https://lore.kernel.org/linux-rockchip/20240325153850.189128-5-sebastian.reichel@collabora.com/Signed-off-by: Dragan Simic <dsimic@manjaro.org>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/0f3759ee390f245dac447bbee038445ddfecbec0.1711383286.git.dsimic@manjaro.orgSigned-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3588-quartzpro64.dts

@@ -285,6 +285,12 @@ &gmac0_rgmii_clk
 	status = "okay";
 };
 
+&gpu {
+	mali-supply = <&vdd_gpu_s0>;
+	sram-supply = <&vdd_gpu_mem_s0>;
+	status = "okay";
+};
+
 &i2c2 {
 	status = "okay";
 
@@ -491,11 +497,15 @@ rk806_dvs3_null: dvs3-null-pins {
 		regulators {
 			vdd_gpu_s0: dcdc-reg1 {
 				regulator-name = "vdd_gpu_s0";
+				/* regulator coupling requires always-on */
+				regulator-always-on;
 				regulator-boot-on;
 				regulator-enable-ramp-delay = <400>;
 				regulator-min-microvolt = <550000>;
 				regulator-max-microvolt = <950000>;
 				regulator-ramp-delay = <12500>;
+				regulator-coupled-with = <&vdd_gpu_mem_s0>;
+				regulator-coupled-max-spread = <10000>;
 
 				regulator-state-mem {
 					regulator-off-in-suspend;
@@ -545,11 +555,15 @@ regulator-state-mem {
 
 			vdd_gpu_mem_s0: dcdc-reg5 {
 				regulator-name = "vdd_gpu_mem_s0";
+				/* regulator coupling requires always-on */
+				regulator-always-on;
 				regulator-boot-on;
 				regulator-enable-ramp-delay = <400>;
 				regulator-min-microvolt = <675000>;
 				regulator-max-microvolt = <950000>;
 				regulator-ramp-delay = <12500>;
+				regulator-coupled-with = <&vdd_gpu_s0>;
+				regulator-coupled-max-spread = <10000>;
 
 				regulator-state-mem {
 					regulator-off-in-suspend;