genirq/devres: Remove excess parameter from kernel doc

Building with 'make W=1' complains:

  CC      kernel/irq/devres.o
kernel/irq/devres.c:104: warning: Excess function parameter 'thread_fn'
			 description in 'devm_request_any_context_irq'

Remove it.

Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/31207.1552378676@turing-police