x86: move pci fixup to pci-dma.c

via_no_dac provides a fixup that is the same for both
architectures. Move it to pci-dma.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 914846d..d82517d 100644
--- a/include/asm-x86/dma-mapping.h
+++ b/include/asm-x86/dma-mapping.h
@@ -14,6 +14,7 @@
 extern int iommu_merge;
 extern struct device fallback_dev;
 extern int panic_on_overflow;
+extern int forbid_dac;
 
 struct dma_mapping_ops {
 	int             (*mapping_error)(dma_addr_t dma_addr);
@@ -223,6 +224,5 @@
 extern void *
 dma_mark_declared_memory_occupied(struct device *dev,
 				  dma_addr_t device_addr, size_t size);
-extern int forbid_dac;
 #endif /* CONFIG_X86_32 */
 #endif