KVM: arm64: vgic: Drop stale comment on IRQ active state

While LPIs lack an active state, KVM unconditionally folds the active
state from the LR into the vgic_irq struct meaning this field cannot be
'creatively' reused for something else.

Drop the misleading comment to reflect this.

Link: https://lore.kernel.org/r/20250905100531.282980-2-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

include/kvm/arm_vgic.h

@@ -139,7 +139,7 @@ struct vgic_irq {
 	bool pending_latch;		/* The pending latch state used to calculate
 					 * the pending state for both level
 					 * and edge triggered IRQs. */
-	bool active;			/* not used for LPIs */
+	bool active;
 	bool enabled;
 	bool hw;			/* Tied to HW IRQ */
 	struct kref refcount;		/* Used for LPIs */