arm64: dts: rockchip: Add vcc supply for SPI Flash on NanoPC-T6

FriendlyELEC NanoPC-T6 LTS schematics shows VCC_1V8_S3 being used to
power SPI NOR chip.

This fixes the following kernel message:

spi-nor spi5.0: supply vcc not found, using dummy regulator

Signed-off-by: Marcin Juszkiewicz <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Heiko Stuebner <[email protected]>

Author: hrw

arch/arm64/boot/dts/rockchip/rk3588-nanopc-t6.dtsi

@@ -731,6 +731,7 @@
 		spi-max-frequency = <104000000>;
 		spi-rx-bus-width = <4>;
 		spi-tx-bus-width = <1>;
+		vcc-supply = <&vcc_1v8_s3>;
 	};
 };