arm64: dts: rockchip: fix regulator name on rk3399-rock-4

fix regulator name

ref:
 https://dl.radxa.com/rockpi4/docs/hw/rockpi4/rockpi4_v13_sch_20181112.pdf



Signed-off-by: FUKAUMI Naoki <naoki@radxa.com>
Link: https://lore.kernel.org/r/20220909195006.127957-4-naoki@radxa.com


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