dma-bcm2708: Fix module compilation of CONFIG_DMA_BCM2708

bcm2708-dmaengine.c defines functions like bcm_dma_start which are
defined as well in dma-bcm2708.h as inline versions when
CONFIG_DMA_BCM2708 is not defined. This works fine when
CONFIG_DMA_BCM2708 is built in, but when it is selected as module build
fails with redefinition errors because in the build system when
CONFIG_DMA_BCM2708 is selected as module, the macro becomes
CONFIG_DMA_BCM2708_MODULE.

This patch makes the header use CONFIG_DMA_BCM2708_MODULE too when
available.

Fixes raspberrypi#2056

Signed-off-by: Andrei Gherzan <andrei@gherzan.com>

include/linux/platform_data/dma-bcm2708.h

@@ -75,7 +75,7 @@ struct bcm2708_dma_cb {
 struct scatterlist;
 struct platform_device;
 
-#ifdef CONFIG_DMA_BCM2708
+#if defined(CONFIG_DMA_BCM2708) || defined(CONFIG_DMA_BCM2708_MODULE)
 
 int bcm_sg_suitable_for_dma(struct scatterlist *sg_ptr, int sg_len);
 void bcm_dma_start(void __iomem *dma_chan_base, dma_addr_t control_block);
@@ -138,6 +138,6 @@ static inline int bcm_dmaman_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#endif /* CONFIG_DMA_BCM2708 */
+#endif /* CONFIG_DMA_BCM2708 || CONFIG_DMA_BCM2708_MODULE */
 
 #endif /* _PLAT_BCM2708_DMA_H */