riscv: dts: sophgo: add device tree for LicheeRV Nano

Import a slightly modified version of the LicheeRV Nano and SG2002
device trees from the Linux Kernel. The current supported IPs are UART,
MMC, Timer, PLIC and CLINT.

Signed-off-by: Thomas Bonnefille <thomas.bonnefille@bootlin.com>
diff --git a/arch/riscv/dts/Makefile b/arch/riscv/dts/Makefile
index de35658..e054968 100644
--- a/arch/riscv/dts/Makefile
+++ b/arch/riscv/dts/Makefile
@@ -2,6 +2,7 @@
 
 dtb-$(CONFIG_TARGET_ANDES_AE350) += ae350_32.dtb ae350_64.dtb
 dtb-$(CONFIG_TARGET_MILKV_DUO) += cv1800b-milkv-duo.dtb
+dtb-$(CONFIG_TARGET_LICHEERV_NANO) += sg2002-licheerv-nano-b.dtb
 dtb-$(CONFIG_TARGET_QEMU_VIRT) += qemu-virt32.dtb qemu-virt64.dtb
 dtb-$(CONFIG_TARGET_OPENPITON_RISCV64) += openpiton-riscv64.dtb
 dtb-$(CONFIG_TARGET_SIFIVE_UNLEASHED) += hifive-unleashed-a00.dtb