RISC-V: KVM: Update firmware counters for various events

SBI PMU specification defines few firmware counters which can be
used by the guests to collect the statstics about various traps
occurred in the host.

Update these counters whenever a corresponding trap is taken

Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20241224-kvm_guest_stat-v2-2-08a77ac36b02@rivosinc.com


Signed-off-by: Anup Patel <anup@brainfault.org>