riscv: kexec: Fixup irq controller broken in kexec crash path

riscv: kexec: Fixup irq controller broken in kexec crash path

If a crash happens on cpu3 and all interrupts are binding on cpu0, the
bad irq routing will cause a crash kernel which can't receive any irq.
Because crash kernel won't clean up all harts' PLIC enable bits in
enable registers. This patch is similar to 0e735dc4705f ("ARM: 7316/1:
kexec: EOI active and mask all interrupts in kexec crash path") and
1edcc040848f ("arm64: kdump: implement machine_crash_shutdown()"), and
PowerPC also has the same mechanism.

Fixes: 6bab032a4f17 ("RISC-V: Add kexec support")
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Xianting Tian <xianting.tian@linux.alibaba.com>
Cc: Nick Kossifidis <mick@ics.forth.gr>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20221020141603.2856206-2-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>