arm64: dts: rockchip: Enable internal SPI flash for ROCK Pi 4A/B/C

The ROCK Pi 4A, ROCK Pi 4B and ROCK Pi 4C boards contain a nor-flash chip
connected to spi1. Enable spi1 and add the device node.

This patch has been tested on ROCK Pi 4A.

Signed-off-by: Stefan Nagy <stefan.nagy@ixypsilon.net>
Link: https://lore.kernel.org/r/20230811201118.15066-1-stefan.nagy@ixypsilon.net


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