From: Philippe Mathieu-Daudé <f4bug@amsat.org>

Except hw/core/irq.c which implements the forward-declared opaque
qemu_irq structure, hw/adc/zynq-xadc.{c,h} are the only files not
using the typedef. Fix this single exception.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

$ git grep --files-with-matches --perl-regexp "\bIRQState\b"
hw/core/irq.c
include/qemu/typedefs.h

Reviewed-By: Bernhard Beschow <shentey@gmail.com>