arm64: dts: rockchip: Add vcc-supply to SPI flash on rk3328-rock64

As described on page 6 of the Rock64 schematics for both v2.0 and v3.0
the SPI Flash's VCC connector is connected to the VCC_IO power source.

This fixes the following warning:

  spi-nor spi0.0: supply vcc not found, using dummy regulator

Signed-off-by: Diederik de Haas <didi.debian@cknow.org>
Link: https://lore.kernel.org/r/20250425092601.56549-2-didi.debian@cknow.org


Signed-off-by: Heiko Stuebner <heiko@sntech.de>