LoongArch: Increase MAX_IO_PICS up to 8

Begin with Loongson-3C6000, the number of PCI host can be as many as
8 for multi-chip machines, and this number should be the same for I/O
interrupt controllers. To support these machines we also increase the
MAX_IO_PICS up to 8.

Cc: stable@vger.kernel.org
Tested-by: Mingcong Bai <baimingcong@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

Author: chenhuacai

arch/loongarch/include/asm/irq.h

@@ -53,7 +53,7 @@ void spurious_interrupt(void);
 #define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
 void arch_trigger_cpumask_backtrace(const struct cpumask *mask, int exclude_cpu);
 
-#define MAX_IO_PICS 2
+#define MAX_IO_PICS 8
 #define NR_IRQS	(64 + NR_VECTORS * (NR_CPUS + MAX_IO_PICS))
 
 struct acpi_vector_group {