target/riscv: Declare csr_ops[] with a known size

csr_ops[] is currently declared with an unknown size in cpu.h.
Since the array size is known, let's do a complete declaration.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 1611024723-14293-1-git-send-email-bmeng.cn@gmail.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/cpu.h

@@ -487,7 +487,7 @@ enum {
 };
 
 /* CSR function table */
-extern riscv_csr_operations csr_ops[];
+extern riscv_csr_operations csr_ops[CSR_TABLE_SIZE];
 
 void riscv_get_csr_ops(int csrno, riscv_csr_operations *ops);
 void riscv_set_csr_ops(int csrno, riscv_csr_operations *ops);