target/riscv: cpu: Implement get_arch_id callback

Implement the callback for getting the architecture-dependent CPU ID ie
mhartid.

Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20230303065055.915652-2-mchitale@ventanamicro.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
1 file changed