RISC-V: Support for 64bit hartid on RV64 platforms

The hartid can be a 64bit value on RV64 platforms. This series updates
the code so that 64bit hartid can be supported on RV64 platforms.

* 'riscv-64bit_hartid' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux.git:
  riscv/efi_stub: Add 64bit boot-hartid support on RV64
  riscv: cpu: Add 64bit hartid support on RV64
  riscv: smp: Add 64bit hartid support on RV64
  riscv: spinwait: Fix hartid variable type
  riscv: cpu_ops_sbi: Add 64bit hartid support on RV64