arm64: dts: rockchip: Add NanoPC T6

Add the NanoPC T6, a single board computer from FriendlyElec based on
the RK3588.

Initial device tree supports debug UART, SD, eMMC, PCIe 3, PMIC,
and 40 pin GPIO assignments.
Signed-off-by: Thomas McKahan <tmckahan@singleboardsolutions.com>
Link: https://lore.kernel.org/r/20230809112120.99-3-tmckahan@singleboardsolutions.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/Makefile

@@ -100,6 +100,7 @@ dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3568-rock-3a.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588-edgeble-neu6a-io.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588-edgeble-neu6b-io.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588-evb1-v10.dtb
+dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588-nanopc-t6.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588-rock-5b.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588s-indiedroid-nova.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588s-khadas-edge2.dtb