RISC-V: fixups to work with crash tool

A handful of fixes to our kexec/crash kernel support that allow crash
tool to function.

Link: https://lore.kernel.org/r/mhng-f5fdaa37-e99a-4214-a297-ec81f0fed0c1@palmer-mbp2014

* commit 'f9293ad4':
  RISC-V: Add modules to virtual kernel memory layout dump
  RISC-V: Fixup schedule out issue in machine_crash_shutdown()
  RISC-V: Fixup get incorrect user mode PC for kernel mode regs
  RISC-V: kexec: Fixup use of smp_processor_id() in preemptible context