arm64: dts: rockchip: Move ep-gpios property to nanopc-t4 from nanopi4

arm64: dts: rockchip: Move ep-gpios property to nanopc-t4 from nanopi4

Only the NanoPC T4 hs the PCIe reset pin routed to the SoC. For the
NanoPi M4 family, no such signal is routed to the expansion header on
the base board.

As the schematics for the expansion board were not released, it is
unclear how this is handled, but the likely answer is that the signal
is always pulled high.

Move the ep-gpios property from the common nanopi4.dtsi file to the
board level nanopc-t4.dts file. This makes the nanopi-m4 lack ep-gpios,
matching the board design.

A companion patch "PCI: rockchip: make ep_gpio optional" for the Linux
driver is required, as the driver currently requires the property to be
present.

Fixes: e7a095908227 ("arm64: dts: rockchip: Add devicetree for NanoPC-T4")
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Link: https://lore.kernel.org/r/20210121162321.4538-4-wens@kernel.org
Signed-off-by: Heiko Stuebner <heiko@sntech.de>