riscv: dts: sophgo: Add clk node and sdhci node

Add clk node and sdhci node for cv18xx SoCs according to patches from Linux
kernel.

clk: https://lore.kernel.org/all/IA1PR20MB4953F9AD6792013B54636F05BB4F2@IA1PR20MB4953.namprd20.prod.outlook.com/
sdhci: https://lore.kernel.org/all/20240217144826.3944-1-jszhang@kernel.org/

Signed-off-by: Kongyang Liu <seashell11234455@gmail.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
diff --git a/arch/riscv/dts/cv1800b.dtsi b/arch/riscv/dts/cv1800b.dtsi
index 165e9e3..baf6418 100644
--- a/arch/riscv/dts/cv1800b.dtsi
+++ b/arch/riscv/dts/cv1800b.dtsi
@@ -16,3 +16,7 @@
 &clint {
 	compatible = "sophgo,cv1800b-clint", "thead,c900-clint";
 };
+
+&clk {
+	compatible = "sophgo,cv1800-clk";
+};