[ARM] Move ISA DMA bus_to_virt() out of set_dma_addr()

Allow the compiler to optimise the bus_to_virt(virt_to_bus())
transformation in the ARM ISA DMA interface.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/include/asm-arm/dma.h b/include/asm-arm/dma.h
index ef41df43a..1c7087f 100644
--- a/include/asm-arm/dma.h
+++ b/include/asm-arm/dma.h
@@ -91,7 +91,9 @@
  * especially since some DMA architectures don't update the
  * DMA address immediately, but defer it to the enable_dma().
  */
-extern void set_dma_addr(dmach_t channel, unsigned long physaddr);
+extern void __set_dma_addr(dmach_t channel, void *addr);
+#define set_dma_addr(channel, addr)				\
+	__set_dma_addr(channel, bus_to_virt(addr))
 
 /* Set the DMA byte count for this channel
  *