LoongArch: Define ARCH_IRQ_INIT_FLAGS as IRQ_NOPROBE

Currently we call irq_set_noprobe() in a loop for all IRQs, but indeed
it only works for IRQs below NR_IRQS_LEGACY because at init_IRQ() only
legacy interrupts have been allocated.

Instead, we can define ARCH_IRQ_INIT_FLAGS as IRQ_NOPROBE in asm/hwirq.h
and the core will automatically set the flag for all interrupts.
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn>

arch/loongarch/include/asm/hw_irq.h

@@ -9,6 +9,8 @@
 
 extern atomic_t irq_err_count;
 
+#define ARCH_IRQ_INIT_FLAGS	IRQ_NOPROBE
+
 /*
  * interrupt-retrigger: NOP for now. This may not be appropriate for all
  * machines, we'll see ...

arch/loongarch/kernel/irq.c

@@ -102,9 +102,6 @@ void __init init_IRQ(void)
 	mp_ops.init_ipi();
 #endif
 
-	for (i = 0; i < NR_IRQS; i++)
-		irq_set_noprobe(i);
-
 	for_each_possible_cpu(i) {
 		page = alloc_pages_node(cpu_to_node(i), GFP_KERNEL, order);