irqchip: tegra: Add DT-based support for legacy interrupt controller

irqchip: tegra: Add DT-based support for legacy interrupt controller

Tegra's LIC (Legacy Interrupt Controller) has been so far only
supported as a weird extension of the GIC, which is not exactly
pretty.

The stacked IRQ domain framework fits this pretty well, and allows
the LIC code to be turned into a standalone irqchip. In the process,
make the driver DT aware, something that was sorely missing from
the mach-tegra implementation.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1426088583-15097-3-git-send-email-marc.zyngier@arm.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>