arm64: dts: rockchip: fix fixed-regulator renames on rk3399-gru devices

rk3399-gru chromebooks have a regulator chains where one named regulator
supplies multiple regulators pp900-usb pp900_pcie that supply
the named peripherals.

The dtsi used somewhat creative structure to describe that in creating
the base node 3 times with different phandles and describing the EC
dependency in a comment.

This didn't register in the recent regulator-node renaming, as the
additional nodes were empty, so adapt the missing node names for now.

Fixes: 5c96e633 ("arm64: dts: rockchip: adapt regulator nodenames to preferred form")
Tested-by: Vicente Bergas <vicencb@gmail.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20250116143631.3650469-1-heiko@sntech.de