xhci: remove GFP_DMA flag from allocation

There is no reason to restrict allocations to the first 16MB ISA DMA
addresses.

It is causing problems in a virtualization setup with enabled IOMMU
(x86_64). The result is that USB is not working in the VM.

CC: <stable@vger.kernel.org>
Signed-off-by: NMatthias Lange <matthias.lange@kernkonzept.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-mem.c

@@ -56,7 +56,7 @@ static struct xhci_segment *xhci_segment_alloc(struct xhci_hcd *xhci,
 	}
 
 	if (max_packet) {
-		seg->bounce_buf = kzalloc(max_packet, flags | GFP_DMA);
+		seg->bounce_buf = kzalloc(max_packet, flags);
 		if (!seg->bounce_buf) {
 			dma_pool_free(xhci->segment_pool, seg->trbs, dma);
 			kfree(seg);