util/cpuinfo-riscv: Support host/cpuinfo.h for riscv

Move detection code out of tcg, similar to other hosts.

Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

host/include/riscv/host/cpuinfo.h

@@ -0,0 +1,23 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ * Host specific cpu identification for RISC-V.
+ */
+
+#ifndef HOST_CPUINFO_H
+#define HOST_CPUINFO_H
+
+#define CPUINFO_ALWAYS          (1u << 0)  /* so cpuinfo is nonzero */
+#define CPUINFO_ZBA             (1u << 1)
+#define CPUINFO_ZBB             (1u << 2)
+#define CPUINFO_ZICOND          (1u << 3)
+
+/* Initialized with a constructor. */
+extern unsigned cpuinfo;
+
+/*
+ * We cannot rely on constructor ordering, so other constructors must
+ * use the function interface rather than the variable above.
+ */
+unsigned cpuinfo_init(void);
+
+#endif /* HOST_CPUINFO_H */