RISC-V: KVM: Redirect AMO load/store access fault traps to guest

RISC-V: KVM: Redirect AMO load/store access fault traps to guest

The KVM RISC-V does not delegate AMO load/store access fault traps to
VS-mode (hedeleg) so typically M-mode takes these traps and redirects
them back to HS-mode. However, upon returning from M-mode, the KVM
RISC-V running in HS-mode terminates VS-mode software.

The KVM RISC-V should redirect AMO load/store access fault traps back
to VS-mode and let the VS-mode trap handler determine the next steps.

Signed-off-by: Yu-Wei Hsu <betterman5240@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20240429092113.70695-1-betterman5240@gmail.com
Signed-off-by: Anup Patel <anup@brainfault.org>