genirq: Remove __request_percpu_irq() helper

genirq: Remove __request_percpu_irq() helper

With the IRQ timing stuff being gone, there is no need to specify a flag
when requesting a percpu interrupt. Not only IRQF_TIMER was the only flag
(set of flags actually) allowed, but nobody ever passed it.

Get rid of __request_percpu_irq(), which was only getting 0 as flags, and
promote request_percpu_irq_affinity() as its replacement.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Link: https://patch.msgid.link/20251210082242.360936-3-maz@kernel.org