riscv: print hartid on bringup

riscv: print hartid on bringup

Firmware randomly releases cores, so CPU numbers don't linearly map
to hartids. When the system has an exception, we care more about hartids.
Adding "dyndbg="file smpboot.c +p" loglevel=8" to the cmdline can output
the hartid.

Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20250303083424.14309-1-cuiyunhui@bytedance.com
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>