arm64: dts: rockchip: Add vcc-supply to SPI flash on rk3588-rock-5b

arm64: dts: rockchip: Add vcc-supply to SPI flash on rk3588-rock-5b

The Radxa Rock 5B component placement document identifies the SPI Nor
Flash chip as 'U4300' which is described on page 25 of the Schematic
v1.45. There we can see that the VCC connector is connected to the
VCC_3V3_S3 power source.

This fixes the following warning:

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

Signed-off-by: Diederik de Haas <didi.debian@cknow.org>
Link: https://lore.kernel.org/r/20250425092601.56549-5-didi.debian@cknow.org
Signed-off-by: Heiko Stuebner <heiko@sntech.de>