[fsbl] add fsbl for cv181x/cv180x

Change-Id: I6809bc5016d4bc148f62be2ed3f8e928ec111f19

fsbl/lib/cpu/riscv/misc_helpers.c

@@ -0,0 +1,11 @@
+#include <string.h>
+
+void *memcpy16(void *dest, const void *src, size_t length)
+{
+	return memcpy(dest, src, length);
+}
+void zeromem(void *dst, size_t size)
+{
+	memset(dst, 0, size);
+}
+