irqchip/loongson-eiointc: Rename CPUHP_AP_IRQ_LOONGARCH_STARTING

Rename CPUHP_AP_IRQ_LOONGARCH_STARTING to CPUHP_AP_IRQ_EIOINTC_STARTING
because the upcoming AVECINTC irqchip driver will introduce a new state
and so both are clearly identifiable.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240823103936.25092-3-zhangtianyang@loongson.cn