[PATCH] x86_64: Calgary IOMMU - move valid_dma_direction into the callers

Based on Andi Kleen's comments on the original Calgary patch, move
valid_dma_direction into the calling functions.

Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Jon Mason <jdmason@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>