irqchip/tegra: Fix sparse warnings on __iomem

Fix the following warnings from sparse due to casting to/from __iomem
annotated variables:

drivers/irqchip/irq-tegra.c:93:31: warning: incorrect type in initializer (different address spaces)
drivers/irqchip/irq-tegra.c:93:31:    expected void [noderef] <asn:2>*base
drivers/irqchip/irq-tegra.c:93:31:    got void *chip_data
drivers/irqchip/irq-tegra.c:93:31: warning: incorrect type in initializer (different address spaces)
drivers/irqchip/irq-tegra.c:93:31:    expected void [noderef] <asn:2>*base
drivers/irqchip/irq-tegra.c:93:31:    got void *chip_data
drivers/irqchip/irq-tegra.c:93:31: warning: incorrect type in initializer (different address spaces)
drivers/irqchip/irq-tegra.c:93:31:    expected void [noderef] <asn:2>*base
drivers/irqchip/irq-tegra.c:93:31:    got void *chip_data
drivers/irqchip/irq-tegra.c:93:31: warning: incorrect type in initializer (different address spaces)
drivers/irqchip/irq-tegra.c:93:31:    expected void [noderef] <asn:2>*base
drivers/irqchip/irq-tegra.c:93:31:    got void *chip_data
drivers/irqchip/irq-tegra.c:269:57: warning: incorrect type in argument 5 (different address spaces)
drivers/irqchip/irq-tegra.c:269:57:    expected void *chip_data
drivers/irqchip/irq-tegra.c:269:57:    got void [noderef] <asn:2>*<noident>

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://lkml.kernel.org/r/1465302292-4840-1-git-send-email-ben.dooks@codethink.co.uk


Signed-off-by: Jason Cooper <jason@lakedaemon.net>