KVM: arm64: Remove evaluation of timer state in kvm_cpu_has_pending_timer()

KVM: arm64: Remove evaluation of timer state in kvm_cpu_has_pending_timer()

The vgic-v5 code added some evaluations of the timers in a helper funtion
(kvm_cpu_has_pending_timer()) that is called to determine whether
the vcpu can wake-up.

But looking at the timer there is wrong:

- we want to see timers that are signalling an interrupt to the
  vcpu, and not just that have a pending interrupt

- we already have kvm_arch_vcpu_runnable() that evaluates the
  state of interrupts

- kvm_cpu_has_pending_timer() really is about WFIT, as the timeout
  does not generate an interrupt, and is therefore distinct from
  the point above

As a consequence, revert these changes and teach vgic_v5_has_pending_ppi()
about checking for pending HW interrupts instead.

Fixes: 9491c63b6cd7b ("KVM: arm64: gic-v5: Enlighten arch timer for GICv5")
Link: https://sashiko.dev/#/patchset/20260319154937.3619520-1-sascha.bischoff%40arm.com
Link: https://patch.msgid.link/20260401103611.357092-13-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>