sysreset: provide SBI based sysreset driver

Provide sysreset driver using the SBI system reset extension.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Samuel Holland <samuel@sholland.org>
diff --git a/arch/riscv/cpu/cpu.c b/arch/riscv/cpu/cpu.c
index c894ac1..8e49b6d 100644
--- a/arch/riscv/cpu/cpu.c
+++ b/arch/riscv/cpu/cpu.c
@@ -6,6 +6,7 @@
 #include <common.h>
 #include <cpu.h>
 #include <dm.h>
+#include <dm/lists.h>
 #include <init.h>
 #include <log.h>
 #include <asm/encoding.h>
@@ -138,7 +139,17 @@
 
 int arch_early_init_r(void)
 {
-	return riscv_cpu_probe();
+	int ret;
+
+	ret = riscv_cpu_probe();
+	if (ret)
+		return ret;
+
+	if (IS_ENABLED(CONFIG_SYSRESET_SBI))
+		device_bind_driver(gd->dm_root, "sbi-sysreset",
+				   "sbi-sysreset", NULL);
+
+	return 0;
 }
 
 /**