x86 gart: rename CONFIG_IOMMU to CONFIG_GART_IOMMU

This patch renames the IOMMU config option to GART_IOMMU because in fact it
means the GART and not general support for an IOMMU on x86.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Acked-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index eb4ac47..316a746 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -434,7 +434,7 @@
 		if (dma) {
 			io->urbs [i]->transfer_dma = sg_dma_address (sg + i);
 			len = sg_dma_len (sg + i);
-#if defined(CONFIG_HIGHMEM) || defined(CONFIG_IOMMU)
+#if defined(CONFIG_HIGHMEM) || defined(CONFIG_GART_IOMMU)
 			io->urbs[i]->transfer_buffer = NULL;
 #else
 			io->urbs[i]->transfer_buffer = sg_virt(&sg[i]);