[RFC PATCH 1/5] x86, irq: Remove not needed irq_reserve_irqs calling

Now x86 only support sparseirq path, for that path, calling path like: early_irq_init ==> arch_probe_nr_irqs : return legacy irq number ==> alloc_desc for legacy irqs and set bits in allocated_irqs ==> arch_early_irq_init

[RFC PATCH 1/5] x86, irq: Remove not needed irq_reserve_irqs calling

Now x86 only support sparseirq path, for that path, calling path like: early_irq_init == arch_probe_nr_irqs : return legacy irq number == alloc_desc for legacy irqs and set bits in allocated_irqs == arch_early_irq_init