arm64: dts: rockchip: set vdd_gpu regulator on rk3568-evb1-v10 to always on

As discussed in [0], the Rockchip power domain driver does not consider
the external supplies (such as VDD_GPU on the RK3568 EVB1). In the scope of
this discussion it has been pointed out that turning this voltage on/off
on the fly is not explicitly supported. This patch follows the other RK356x
boards by example and sets the vdd_gpu regulator to always on.

[0] https://lore.kernel.org/linux-rockchip/20211217130919.3035788-1-s.hauer@pengutronix.de/Signed-off-by: Michael Riesch <michael.riesch@wolfvision.net>
Link: https://lore.kernel.org/r/20220223112008.1316132-1-michael.riesch@wolfvision.netSigned-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3568-evb1-v10.dts

@@ -233,6 +233,7 @@ regulator-state-mem {
 
 			vdd_gpu: DCDC_REG2 {
 				regulator-name = "vdd_gpu";
+				regulator-always-on;
 				regulator-init-microvolt = <900000>;
 				regulator-initial-mode = <0x2>;
 				regulator-min-microvolt = <500000>;