KVM: arm64: Fix hardware enable/disable flows for pKVM

KVM: arm64: Fix hardware enable/disable flows for pKVM

When running in protected mode, the hyp stub is disabled after pKVM is
initialized, meaning the host cannot enable/disable the hyp at
runtime. As such, kvm_arm_hardware_enabled is always 1 after
initialization, and kvm_arch_hardware_enable() never enables the vgic
maintenance irq or timer irqs.

Unconditionally enable/disable the vgic + timer irqs in the respective
calls, instead relying on the percpu bookkeeping in the generic code
to keep track of which cpus have the interrupts unmasked.

Fixes: 466d27e48d7c ("KVM: arm64: Simplify the CPUHP logic")
Reported-by: Oliver Upton <oliver.upton@linux.dev>
Suggested-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Link: https://lore.kernel.org/r/20230719175400.647154-1-rananta@google.com
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>