irqchip/tegra: Switch to use irq_domain_free_irqs_common

Current code calls irq_domain_alloc_irqs_parent() in .alloc,
so it should call irq_domain_free_irqs_parent() accordingly in .free.
Fix it by switching to use irq_domain_free_irqs_common() instead of
the open-coded private implementation.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: linux-tegra@vger.kernel.org
Link: http://lkml.kernel.org/r/1458477845.28679.1.camel@ingics.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>