dma: improve section assignment in i.MX31 IPU DMA driver

The i.MX31 IPU DMA driver is a platform driver, but doesn't need hotplug, so we
can use __init and __exit function attributes.

Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/dma/ipu/ipu_irq.c b/drivers/dma/ipu/ipu_irq.c
index 83f532c..dd8ebc7 100644
--- a/drivers/dma/ipu/ipu_irq.c
+++ b/drivers/dma/ipu/ipu_irq.c
@@ -352,7 +352,7 @@
 };
 
 /* Install the IRQ handler */
-int ipu_irq_attach_irq(struct ipu *ipu, struct platform_device *dev)
+int __init ipu_irq_attach_irq(struct ipu *ipu, struct platform_device *dev)
 {
 	struct ipu_platform_data *pdata = dev->dev.platform_data;
 	unsigned int irq, irq_base, i;