riscv: hart: Add a "hartid-base" property to RISC-V hart array

At present each hart's hartid in a RISC-V hart array is assigned
the same value of its index in the hart array. But for a system
that has multiple hart arrays, this is not the case any more.

Add a new "hartid-base" property so that hartid number can be
assigned based on the property value.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

include/hw/riscv/riscv_hart.h

@@ -35,6 +35,7 @@ typedef struct RISCVHartArrayState {
 
     /*< public >*/
     uint32_t num_harts;
+    uint32_t hartid_base;
     char *cpu_type;
     RISCVCPU *harts;
 } RISCVHartArrayState;