x86: move dma_map_sg to common header

the old i386 implementation is moved to pci-base_32.c

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/asm-x86/dma-mapping.h b/include/asm-x86/dma-mapping.h
index bb0378f..0901154 100644
--- a/include/asm-x86/dma-mapping.h
+++ b/include/asm-x86/dma-mapping.h
@@ -75,5 +75,11 @@
 		dma_ops->unmap_single(dev, addr, size, direction);
 }
 
-
+static inline int
+dma_map_sg(struct device *hwdev, struct scatterlist *sg,
+	   int nents, int direction)
+{
+	BUG_ON(!valid_dma_direction(direction));
+	return dma_ops->map_sg(hwdev, sg, nents, direction);
+}
 #endif