KVM: PPC: Book3S HV: Update guest state entry/exit accounting to new API

Update the guest state and timing entry/exit accounting to use the new
API, which was introduced following issues found[1]. KVM HV does
possibly call instrumented code inside the guest context, and it does
call srcu inside the guest context which is fragile at best.

Switch to the new API, moving the guest context inside the
srcu_read_lock/unlock region.

[1] https://lore.kernel.org/lkml/20220201132926.3301912-1-mark.rutland@arm.com/



Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220908132545.4085849-3-npiggin@gmail.com