arm64: dts: rockchip: rename flash nodenames

Nodes with compatible "jedec,spi-nor" are now checked with
jedec,spi-nor.yaml and mtd.yaml. The pattern is now
"^flash(@.*)?$", so change that for the boards with a
Rockchip SoC.

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Link: https://lore.kernel.org/r/20210711145900.15443-1-jbx6244@gmail.com


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