arm64: dts: rockchip: fix endpoint dtc warning for PX30 ISP

arm64: dts: rockchip: fix endpoint dtc warning for PX30 ISP

dtc complains with the following message for DTSes which use the ISP:

arch/arm64/boot/dts/rockchip/px30.dtsi:1272.19-1276.6: Warning (graph_child_address): /isp@ff4a0000/ports/port@0: graph node has single child node 'endpoint@0', #address-cells/#size-cells are not necessary

Typically, it is expected from the device DTS(I) to update the SoC DTSI
nodes if they have more than one endpoint, so let's assume there's only
one endpoint in port@0 by default, instead of forcing board DTS(I)s to
/delete-property/ address-cells and size-cells to make dtc happy.

Because PX30 PP1516/EVB's endpoint@0 is the only endpoint and
considering its parent node now has no address-cells property, dtc
complains (same messages for PX30 EVB):

arch/arm64/boot/dts/rockchip/px30-pp1516.dtsi:447.29-451.6: Warning (avoid_default_addr_size): /isp@ff4a0000/ports/port@0/endpoint@0: Relying on default #address-cells value
arch/arm64/boot/dts/rockchip/px30-pp1516.dtsi:447.29-451.6: Warning (avoid_default_addr_size): /isp@ff4a0000/ports/port@0/endpoint@0: Relying on default #size-cells value
arch/arm64/boot/dts/rockchip/px30-pp1516-ltk050h3146w-a2.dtb: Warning (avoid_unnecessary_addr_size): Failed prerequisite 'avoid_default_addr_size'
arch/arm64/boot/dts/rockchip/px30-pp1516-ltk050h3146w-a2.dtb: Warning (unique_unit_address_if_enabled): Failed prerequisite 'avoid_default_addr_size'
arch/arm64/boot/dts/rockchip/px30-pp1516.dtsi:447.29-451.6: Warning (graph_endpoint): /isp@ff4a0000/ports/port@0/endpoint@0: graph node '#address-cells' is -1, must be 1
arch/arm64/boot/dts/rockchip/px30-pp1516.dtsi:447.29-451.6: Warning (graph_endpoint): /isp@ff4a0000/ports/port@0/endpoint@0: graph node '#size-cells' is -1, must be 0
arch/arm64/boot/dts/rockchip/px30-pp1516-ltk050h3146w-a2.dtb: Warning (graph_child_address): Failed prerequisite 'graph_endpoint'

so we fix that by removing the reg property. dtc still complains (same
messages for PX30 EVB):

arch/arm64/boot/dts/rockchip/px30-pp1516.dtsi:447.29-450.6: Warning (unit_address_vs_reg): /isp@ff4a0000/ports/port@0/endpoint@0: node has a unit name, but no reg or ranges property

so we also remove the @0 suffix off the node name.

Fixes: 8df7b4537dfb ("arm64: dts: rockchip: add isp node for px30")
Fixes: 474a77395be2 ("arm64: dts: rockchip: hook up camera on px30-evb")
Fixes: 56198acdbf0d ("arm64: dts: rockchip: add px30-pp1516 base dtsi and board variants")
Signed-off-by: Quentin Schulz <quentin.schulz@cherry.de>
Link: https://lore.kernel.org/r/20250610-ringneck-haikou-video-demo-cam-v2-1-de1bf87e0732@cherry.de
Signed-off-by: Heiko Stuebner <heiko@sntech.de>