move dma_mask into struct device

Attached is a patch which moves dma_mask into struct device and cleans up the 
scsi mid-layer to use it (instead of using struct pci_dev).  The advantage to 
doing this is probably most apparent on non-pci bus architectures where 
currently you have to construct a fake pci_dev just so you can get the bounce 
buffers to work correctly.
  
The patch tries to perturb the minimum amount of code, so dma_mask in struct 
device is simply a pointer to the one in pci_dev.  However, it will make it 
easy for me now to add generic device to MCA without having to go the fake pci
route.

drivers/pci/probe.c

@@ -448,6 +448,7 @@ struct pci_dev * __devinit pci_scan_device(struct pci_dev *temp)
 
 	/* now put in global tree */
 	strcpy(dev->dev.bus_id,dev->slot_name);
+	dev->dev.dma_mask = &dev->dma_mask;
 
 	device_register(&dev->dev);
 	return dev;

include/linux/device.h

@@ -303,6 +303,7 @@ struct device {
 					   being off. */
 
 	unsigned char *saved_state;	/* saved device state */
+	u64		*dma_mask;	/* dma mask (if dma'able device) */
 
 	void	(*release)(struct device * dev);
 };