genirq: Export irq_check_status_bit()

One of the users can be built modular:

  ERROR: modpost: "irq_check_status_bit" [drivers/perf/arm_spe_pmu.ko] undefined!

Fixes: fdd02963 ("genirq: Move status flag checks to core")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201227192049.GA195845@roeck-us.net