irqchip: Fix dependencies for archs w/o HAS_IOMEM

Not every arch has io memory. So, unbreak the build by fixing the
dependencies.

Signed-off-by: Richard Weinberger <richard@nod.at>
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/1453760661-1444-19-git-send-email-richard@nod.at
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>